Igor Aharonovich received his B.Sc (2005) and M.Sc (2007) in Materials Eng from the Technion – Israel Institute of Technology under the supervision of Prof Yeshayahu Lifshitz. He then moved to Australia and pursued his PhD studies at the University of Melbourne under the supervision of Prof Steven Prawer. During his PhD, Igor developed experimental techniques to engineer novel, ultra bright single photon emitters in diamond.
In 2011, Igor took a postdoctoral position at Harvard University at the group of Prof Evelyn Hu. His research was focused on nanofabrication of optical cavities out of diamond, SiC and GaN. He also carried out nanophotonic experiments including coupling of emitters to optical cavities, turning of cavity resonances and low temperature high resolution spectroscopy.
In 2013 Igor has joined the School of Physics and Advanced Materials as a Senior Lecturer and a CPD fellow. His research will be focused on wide bandgap semiconductors and their implementation in Nanophotonics and Bio-sensing.
Igor received several international awards including the Pawsey medal (2017), the IEEE Photonics Young Investigator Award (2016) Chancellor Postdoctoral Fellowship from UTS (2013) Harvard Postdoctoral Award for Professional Development (2012), SPIE Research Excellence Award (2010) and Sigma Xi Research grant (2009). He was also awarded the 2013 Discovery Early Career Research Award from the ARC
Visit the Materials Physics and Nanophotonics website for more details
- Co-organized the inaugural Harvard – Australian Diamond Photonics conference, held in Melbourne, Australia in January 2012
- Member of the Materials Research Society, American Physics Society and the SPIE
- Reviewer for top international journals including Physical Review journals, ACS Nano, Nanotechnology, Applied Physics Letters, the National Science Foundation and others.
My research interests are focused on nanoscale engineering of nanophotonic entities to control and guide light at the nanoscale by sculpting nanostructures out of wide bandgap semiconductors. The nanoscale architecture is key component for novel devices such as low power lasers, molecular sensors, optical interconnects and high efficiency light emitters. A number of related projects are currently available, and include (but not limited to):
- Investigation of novel quantum systems in wide bandgap semiconductors
- Development of novel bio-sensors based on fluorescent nanodiamonds
- Investigation of light matter interaction in metallic nanostructures (Plasmonics)
- Simulation and design of new architectures for nanophotonics
PhD/Honors scholarships are available for motivated students who are interested in one of these projects or in any other related topic in the broad field of nanotechnology, materials science and nanophotonics
- Solid State Physics
- Quantum mechanics
Current PhD students
© 2014 Elsevier Ltd. All rights reserved. Diamond nitrogen vacancy (NV) color centers can transform quantum information science into practical quantum information technology, including fast, safe computing. Quantum Information Processing with Diamond looks at the principles of quantum information science, diamond materials, and their applications. Part one provides an introduction to quantum information processing using diamond, as well as its principles and fabrication techniques. Part two outlines experimental demonstrations of quantum information processing using diamond, and the emerging applications of diamond for quantum information science. It contains chapters on quantum key distribution, quantum microscopy, the hybridization of quantum systems, and building quantum optical devices. Part three outlines promising directions and future trends in diamond technologies for quantum information processing and sensing. Quantum Information Processing with Diamond is a key reference for R & D managers in industrial sectors such as conventional electronics, communication engineering, computer science, biotechnology, quantum optics, quantum mechanics, quantum computing, quantum cryptology, and nanotechnology, as well as academics in physics, chemistry, biology, and engineering. * Brings together the topics of diamond and quantum information processing * Looks at applications such as quantum computing, neural circuits, and in vivo monitoring of processes at the molecular scale.
Berhane, A.M., Jeong, K.Y., Bradac, C., Walsh, M., Englund, D., Toth, M. & Aharonovich, I. 2018, 'Photophysics of GaN single-photon emitters in the visible spectral range', Physical Review B, vol. 97, no. 16.View/Download from: Publisher's site
© 2018 American Physical Society. In this work, we present a detailed photophysical analysis of recently discovered, optically stable single-photon emitters (SPEs) in gallium nitride (GaN). Temperature-resolved photoluminescence measurements reveal that the emission lines at 4 K are three orders of magnitude broader than the transform-limited width expected from excited-state lifetime measurements. The broadening is ascribed to ultrafast spectral diffusion. The photophysical study on several emitters at room temperature (RT) reveals an average brightness of (427±215)kCounts/s. Finally, polarization measurements from 14 emitters are used to determine visibility as well as dipole orientation of defect systems within the GaN crystal. Our results underpin some of the fundamental properties of SPEs in GaN both at cryogenic and RT, and define the benchmark for future work in GaN-based single-photon technologies.
Bray, K., Kato, H., Previdi, R., Sandstrom, R., Ganesan, K., Ogura, M., Makino, T., Yamasaki, S., Magyar, A.P., Toth, M. & Aharonovich, I. 2018, 'Single crystal diamond membranes for nanoelectronics.', Nanoscale, vol. 10, no. 8, pp. 4028-4035.View/Download from: Publisher's site
Single crystal, nanoscale diamond membranes are highly sought after for a variety of applications including nanophotonics, nanoelectronics and quantum information science. However, so far, the availability of conductive diamond membranes has remained an unreachable goal. In this work we present a complete nanofabrication methodology for engineering high aspect ratio, electrically active single crystal diamond membranes. The membranes have large lateral directions, exceeding 500 500 m2 and are only several hundreds of nanometers thick. We further realize vertical single crystal p-n junctions made from the diamond membranes that exhibit onset voltages of 10 V and a current of several mA. Moreover, we deterministically introduce optically active color centers into the membranes, and demonstrate for the first time a single crystal nanoscale diamond LED. The robust and scalable approach to engineer the electrically active single crystal diamond membranes offers new pathways for advanced nanophotonic, nanoelectronic and optomechanical devices employing diamond.
We propose and design photonic crystal cavities (PCCs) in hexagonal boron nitride (hBN) for diverse photonic and quantum applications. Two dimensional (2D) hBN flakes contain quantum emitters which are ultra-bright and photostable at room temperature. To achieve optimal coupling of these emitters to optical resonators, fabrication of cavities from hBN is therefore required to maximize the overlap between cavity optical modes and the emitters. Here, we design 2D and 1D PCCs using anisotropic indices of hBN. The influence of underlying substrates and material absorption are investigated, and spontaneous emission rate enhancements are calculated. Our results are promising for future quantum photonic experiments with hBN.
Nguyen, M., Kim, S., Tran, T.T., Xu, Z.-.Q., Kianinia, M., Toth, M. & Aharonovich, I. 2018, 'Nanoassembly of quantum emitters in hexagonal boron nitride and gold nanospheres.', Nanoscale, vol. 10, no. 5, pp. 2267-2274.View/Download from: Publisher's site
The assembly of quantum nanophotonic systems with plasmonic resonators is important for fundamental studies of single photon sources as well as for on-chip information processing. In this work, we demonstrate the controllable nanoassembly of gold nanospheres with ultra-bright narrow-band quantum emitters in 2D layered hexagonal boron nitride (hBN). We utilize an atomic force microscope (AFM) tip to precisely position gold nanospheres to close proximity to the quantum emitters and observe the resulting emission enhancement and fluorescence lifetime reduction. The extreme emitter photostability permits analysis at high excitation powers, and delineation of absorption and emission enhancement caused by the plasmonic resonators. A fluorescence enhancement of over 300% is achieved experimentally for quantum emitters in hBN, with a radiative quantum efficiency of up to 40% and a saturated count rate in excess of 5 106 counts per s. Our results are promising for the future employment of quantum emitters in hBN for integrated nanophotonic devices and plasmonic based nanosensors.
Sandstrom, R., Ke, L., Martin, A., Wang, Z., Kianinia, M., Green, B., Gao, W.B. & Aharonovich, I. 2018, 'Optical properties of implanted Xe color centers in diamond', Optics Communications, vol. 411, pp. 182-185.View/Download from: Publisher's site
© 2017 Elsevier B.V. Optical properties of color centers in diamond have been the subject of intense research due to their promising applications in quantum photonics. In this work we study the optical properties of Xe related color centers implanted into nitrogen rich (type IIA) and an ultrapure, electronic grade diamond. The Xe defect has two zero phonon lines at 794 nm and 811 nm, which can be effectively excited using both green and red excitation, however, its emission in the nitrogen rich diamond is brighter. Near resonant excitation is performed at cryogenic temperatures and luminescence is probed under strong magnetic field. Our results are important towards the understanding of the Xe related defect and other near infrared color centers in diamond.
Tran, T.T., Kianinia, M., Nguyen, M., Kim, S., Xu, Z.Q., Kubanek, A., Toth, M. & Aharonovich, I. 2018, 'Resonant Excitation of Quantum Emitters in Hexagonal Boron Nitride', ACS Photonics, vol. 5, no. 2, pp. 295-300.View/Download from: Publisher's site
© 2017 American Chemical Society. Quantum emitters in layered hexagonal boron nitride (hBN) have recently attracted a great deal of attention as promising single photon sources. In this work, we demonstrate resonant excitation of a single defect center in hBN, one of the most important prerequisites for employment of optical sources in quantum information processing applications. We observe spectral line widths of an hBN emitter narrower than 1 GHz while the emitter experiences spectral diffusion. Temporal photoluminescence measurements reveal an average spectral diffusion time of around 100 ms. An on-resonance photon antibunching measurement is also realized. Our results shed light on the potential use of quantum emitters from hBN in nanophotonics and quantum information processing applications.
Xu, Z.-.Q., Elbadawi, C., Tran, T.T., Kianinia, M., Li, X., Liu, D., Hoffman, T.B., Nguyen, M., Kim, S., Edgar, J.H., Wu, X., Song, L., Ali, S., Ford, M., Toth, M. & Aharonovich, I. 2018, 'Single photon emission from plasma treated 2D hexagonal boron nitride.', Nanoscale, vol. 10, no. 17, pp. 7957-7965.View/Download from: Publisher's site
Artificial atomic systems in solids are becoming increasingly important building blocks in quantum information processing and scalable quantum nanophotonic networks. Amongst numerous candidates, 2D hexagonal boron nitride has recently emerged as a promising platform hosting single photon emitters. Here, we report a number of robust plasma and thermal annealing methods for fabrication of emitters in tape-exfoliated hexagonal boron nitride (hBN) crystals. A two-step process comprising Ar plasma etching and subsequent annealing in Ar is highly robust, and yields an eight-fold increase in the concentration of emitters in hBN. The initial plasma-etching step generates emitters that suffer from blinking and bleaching, whereas the two-step process yields emitters that are photostable at room temperature with emission wavelengths greater than 700 nm. Density functional theory modeling suggests that the emitters might be associated with defect complexes that contain oxygen. This is further confirmed by generating the emitters via annealing hBN in air. Our findings advance the present understanding of the structure of quantum emitters in hBN and enhance the nanofabrication toolkit needed to realize integrated quantum nanophotonic circuits.
Zhou, Y., Wang, Z., Rasmita, A., Kim, S., Berhane, A., Bodrog, Z., Adamo, G., Gali, A., Aharonovich, I. & Gao, W.-.B. 2018, 'Room temperature solid-state quantum emitters in the telecom range.', Science advances, vol. 4, no. 3, p. eaar3580.View/Download from: Publisher's site
On-demand, single-photon emitters (SPEs) play a key role across a broad range of quantum technologies. In quantum networks and quantum key distribution protocols, where photons are used as flying qubits, telecom wavelength operation is preferred because of the reduced fiber loss. However, despite the tremendous efforts to develop various triggered SPE platforms, a robust source of triggered SPEs operating at room temperature and the telecom wavelength is still missing. We report a triggered, optically stable, room temperature solid-state SPE operating at telecom wavelengths. The emitters exhibit high photon purity (~5% multiphoton events) and a record-high brightness of ~1.5 MHz. The emission is attributed to localized defects in a gallium nitride (GaN) crystal. The high-performance SPEs embedded in a technologically mature semiconductor are promising for on-chip quantum simulators and practical quantum communication technologies.
Bishop, J., Fronzi, M., Elbadawi, C., Nikam, V., Pritchard, J., Fröch, J.E., Duong, N.M.H., Ford, M.J., Aharonovich, I., Lobo, C.J. & Toth, M. 2018, 'Deterministic Nanopatterning of Diamond Using Electron Beams.', ACS nano, vol. 12, no. 3, pp. 2873-2882.View/Download from: Publisher's site
Diamond is an ideal material for a broad range of current and emerging applications in tribology, quantum photonics, high-power electronics, and sensing. However, top-down processing is very challenging due to its extreme chemical and physical properties. Gas-mediated electron beam-induced etching (EBIE) has recently emerged as a minimally invasive, facile means to dry etch and pattern diamond at the nanoscale using oxidizing precursor gases such as O2 and H2O. Here we explain the roles of oxygen and hydrogen in the etch process and show that oxygen gives rise to rapid, isotropic etching, while the addition of hydrogen gives rise to anisotropic etching and the formation of topographic surface patterns. We identify the etch reaction pathways and show that the anisotropy is caused by preferential passivation of specific crystal planes. The anisotropy can be controlled by the partial pressure of hydrogen and by using a remote RF plasma source to radicalize the precursor gas. It can be used to manipulate the geometries of topographic surface patterns as well as nano- and microstructures fabricated by EBIE. Our findings constitute a comprehensive explanation of the anisotropic etch process and advance present understanding of electron-surface interactions.
Kianinia, M., Bradac, C., Sontheimer, B., Wang, F., Tran, T.T., Nguyen, M., Kim, S., Xu, Z.-.Q., Jin, D., Schell, A.W., Lobo, C.J., Aharonovich, I. & Toth, M. 2018, 'All-optical control and super-resolution imaging of quantum emitters in layered materials.', Nature communications, vol. 9, no. 1, p. 874.View/Download from: UTS OPUS or Publisher's site
Layered van der Waals materials are emerging as compelling two-dimensional platforms for nanophotonics, polaritonics, valleytronics and spintronics, and have the potential to transform applications in sensing, imaging and quantum information processing. Among these, hexagonal boron nitride (hBN) is known to host ultra-bright, room-temperature quantum emitters, whose nature is yet to be fully understood. Here we present a set of measurements that give unique insight into the photophysical properties and level structure of hBN quantum emitters. Specifically, we report the existence of a class of hBN quantum emitters with a fast-decaying intermediate and a long-lived metastable state accessible from the first excited electronic state. Furthermore, by means of a two-laser repumping scheme, we show an enhanced photoluminescence and emission intensity, which can be utilized to realize a new modality of far-field super-resolution imaging. Our findings expand current understanding of quantum emitters in hBN and show new potential ways of harnessing their nonlinear optical properties in sub-diffraction nanoscopy.
Ardekani, S.M., Dehghani, A., Hassan, M., Kianinia, M., Aharonovich, I. & Gomes, V.G. 2017, 'Two-photon excitation triggers combined chemo-photothermal therapy via doped carbon nanohybrid dots for effective breast cancer treatment', Chemical Engineering Journal, vol. 330, pp. 651-662.View/Download from: UTS OPUS or Publisher's site
© 2017 Elsevier B.V. Remotely triggered drug delivery using nanoparticles is an area of great interest for targeted therapy to fight cancer. In this work, we synthesized photoresponsive nanoparticles to remotely initiate the delivery of doxorubicin (DOX) to 3D cultured human breast cancer cells (MCF-7) via NIR two-photon excitation (TPE) using nitrogen-doped and surface passivated (PEG 200 ) carbon nanohybrid dots (CNDs). On-demand drug delivery relies on bio-compatible, photo-responsive nano-carriers with high quantum yields. A facile (5 min synthesis) one-pot hot plate method was used to synthesize functionalized and surface passivated carbon nanohybrid dots (CND-P) having 53% quantum yield (QY). Compared to CNDs prepared from citric acid (CND-C) and citric acid plus urea (CND-N), CND-P had QY enhanced by factors of 12.6 and 4.4, respectively. The up-converted emission intensity of CND-P was strengthened by a factor of 4.5 over that of CND-N from nitrogen doped CNDs for similar test conditions (wavelength, excitation power and concentration). The drug loading capacity of CND-P was measured to be 0.98 w/w with the ability to release DOX via two-photon excitation (TPE). Intense green luminescence was observed under both 360 and 780 nm lasers using single and two-photon excitations. The highly biocompatible CND-P showed 88% cell viability at concentrations as high as 1100 µg/mL. The combined chemo- and photothermal therapeutic effect of the DOX-loaded CND-P (CND-P@DOX) complex resulted in the death of 78% of the MCF-7 cells compared to 59% with DOX alone.
© 2017 American Physical Society. Solid-state single-photon emitters (SPEs) are one of the prime components of many quantum nanophotonics devices. In this work, we report on an unusual, photoinduced blinking phenomenon of SPEs in gallium nitride. This is shown to be due to the modification in the transition kinetics of the emitter, via the introduction of additional laser-activated states. We investigate and characterize the blinking effect on the brightness of the source and the statistics of the emitted photons. Combining second-order correlation and fluorescence trajectory measurements, we determine the photodynamics of the trap states and characterize power-dependent decay rates and characteristic "off"-time blinking. Our work sheds light into understanding solid-state quantum system dynamics and, specifically, power-induced blinking phenomena in SPEs.
Berhane, A.M., Jeong, K.-.Y., Bodrog, Z., Fiedler, S., Schröder, T., Triviño, N.V., Palacios, T., Gali, A., Toth, M., Englund, D. & Aharonovich, I. 2017, 'Bright Room-Temperature Single-Photon Emission from Defects in Gallium Nitride.', Advanced materials (Deerfield Beach, Fla.), vol. 29, no. 12.View/Download from: UTS OPUS or Publisher's site
Room-temperature quantum emitters in gallium nitride (GaN) are reported. The emitters originate from cubic inclusions in hexagonal lattice and exhibit narrowband luminescence in the red spectral range. The sources are found in different GaN substrates, and therefore are promising for scalable quantum technologies.
Gloag, E.S., Elbadawi, C., Zachreson, C.J., Aharonovich, I., Toth, M., Charles, I.G., Turnbull, L. & Whitchurch, C.B. 2017, 'Micro-Patterned Surfaces That Exploit Stigmergy to Inhibit Biofilm Expansion.', Frontiers in Microbiology, vol. 7, pp. 1-10.View/Download from: UTS OPUS or Publisher's site
Twitching motility is a mode of surface translocation that is mediated by the extension and retraction of type IV pili and which, depending on the conditions, enables migration of individual cells or can manifest as a complex multicellular collective behavior that leads to biofilm expansion. When twitching motility occurs at the interface of an abiotic surface and solidified nutrient media, it can lead to the emergence of extensive self-organized patterns of interconnected trails that form as a consequence of the actively migrating bacteria forging a furrow network in the substratum beneath the expanding biofilm. These furrows appear to direct bacterial movements much in the same way that roads and footpaths coordinate motor vehicle and human pedestrian traffic. Self-organizing systems such as these can be accounted for by the concept of stigmergy which describes self-organization that emerges through indirect communication via persistent signals within the environment. Many bacterial communities are able to actively migrate across solid and semi-solid surfaces through complex multicellular collective behaviors such as twitching motility and flagella-mediated swarming motility. Here, we have examined the potential of exploiting the stigmergic behavior of furrow-mediated trail following as a means of controlling bacterial biofilm expansion along abiotic surfaces. We found that incorporation of a series of parallel micro-fabricated furrows significantly impeded active biofilm expansion by Pseudomonas aeruginosa and Proteus vulgaris. We observed that in both cases bacterial movements tended to be directed along the furrows. We also observed that narrow furrows were most effective at disrupting biofilm expansion as they impeded the ability of cells to self-organize into multicellular assemblies required for escape from the furrows and migration into new territory. Our results suggest that the implementation of micro-fabricated furrows that exploit stigmergy may be a ...
Grosso, G., Moon, H., Lienhard, B., Ali, S., Efetov, D.K., Furchi, M.M., Jarillo-Herrero, P., Ford, M.J., Aharonovich, I. & Englund, D. 2017, 'Tunable and high-purity room temperature single-photon emission from atomic defects in hexagonal boron nitride.', Nature communications, vol. 8, no. 1, p. 705.View/Download from: Publisher's site
Two-dimensional van der Waals materials have emerged as promising platforms for solid-state quantum information processing devices with unusual potential for heterogeneous assembly. Recently, bright and photostable single photon emitters were reported from atomic defects in layered hexagonal boron nitride (hBN), but controlling inhomogeneous spectral distribution and reducing multi-photon emission presented open challenges. Here, we demonstrate that strain control allows spectral tunability of hBN single photon emitters over 6meV, and material processing sharply improves the single photon purity. We observe high single photon count rates exceeding 7106 counts per second at saturation, after correcting for uncorrelated photon background. Furthermore, these emitters are stable to material transfer to other substrates. High-purity and photostable single photon emission at room temperature, together with spectral tunability and transferability, opens the door to scalable integration of high-quality quantum emitters in photonic quantum technologies.Inhomogeneous spectral distribution and multi-photon emission are currently hindering the use of defects in layered hBN as reliable single photon emitters. Here, the authors demonstrate strain-controlled wavelength tuning and increased single photon purity through suitable material processing.
Kianinia, M., Regan, B., Tawfik, S.A., Tran, T.T., Ford, M.J., Aharonovich, I. & Toth, M. 2017, 'Robust Solid-State Quantum System Operating at 800 K', ACS Photonics, vol. 4, no. 4, pp. 768-773.View/Download from: UTS OPUS or Publisher's site
© 2017 American Chemical Society. Realization of quantum information and communications technologies requires robust, stable solid-state single-photon sources. However, most existing sources cease to function above cryogenic or room temperature due to thermal ionization or strong phonon coupling, which impedes their emissive and quantum properties. Here we present an efficient single-photon source based on a defect in a van der Waals crystal that is optically stable and operates at elevated temperatures of up to 800 K. The quantum nature of the source and the photon purity are maintained upon heating to 800 K and cooling back to room temperature. Our report of a robust high-temperature solid-state single photon source constitutes a significant step toward practical, integrated quantum technologies for real-world environments.
Martin, A.A., Filevich, J., Straw, M., Randolph, S., Botman, A., Aharonovich, I. & Toth, M. 2017, 'Radiation-Induced Damage and Recovery of Ultra-Nanocrystalline Diamond: Toward Applications in Harsh Environments.', ACS applied materials & interfaces, vol. 9, no. 45, pp. 39790-39794.View/Download from: Publisher's site
Ultra-nanocrystalline diamond (UNCD) is increasingly being used in the fabrication of devices and coatings due to its excellent tribological properties, corrosion resistance, and biocompatibility. Here, we study its response to irradiation with kiloelectronvolt electrons as a controlled model for extreme ionizing environments. Real time Raman spectroscopy reveals that the radiation-damage mechanism entails dehydrogenation of UNCD grain boundaries, and we show that the damage can be recovered by annealing at 883 K. Our results have significant practical implications for the implementation of UNCD in extreme environment applications, and indicate that the films can be used as radiation sensors.
Schell, A.W., Takashima, H., Tran, T.T., Aharonovich, I. & Takeuchi, S. 2017, 'Coupling Quantum Emitters in 2D Materials with Tapered Fibers', ACS Photonics, vol. 4, no. 4, pp. 761-767.View/Download from: UTS OPUS or Publisher's site
© 2017 American Chemical Society. Realization of integrated photonic circuits on a single chip requires controlled manipulation and integration of solid-state quantum emitters with nanophotonic components. Previous works focused on emitters embedded in a three-dimensional crystal, such as nanodiamonds or quantum dots. In contrast, in this work we demonstrate coupling of a single emitter in a two-dimensional (2D) material, namely, hexagonal boron nitride, with a tapered optical fiber and find a collection efficiency of the system of 10%. Furthermore, due to the single dipole character of the emitter, we were able to analyze the angular emission pattern of the coupled system via back focal plane imaging. The good coupling efficiency to the tapered fiber even allows excitation and detection in a fully fiber coupled way, yielding a true integrated system. Our results provide evidence of the feasibility to efficiently integrate quantum emitters in 2D materials with photonic structures.
Sontheimer, B., Braun, M., Nikolay, N., Sadzak, N., Aharonovich, I. & Benson, O. 2017, 'Photodynamics of quantum emitters in hexagonal boron nitride revealed by low-temperature spectroscopy', Physical Review B, vol. 96, no. 12.View/Download from: Publisher's site
© 2017 American Physical Society. Quantum emitters in hexagonal boron nitride (hBN) have recently emerged as promising bright single photon sources. In this Rapid Communication we investigate in detail their optical properties at cryogenic temperatures. In particular, we perform temperature-resolved photoluminescence studies and measure photon coherence times from the hBN emitters. The obtained value of 81(1)ps translates to a width of 6.5GHz which is higher than the Fourier transform limited value of 32MHz. To account for the photodynamics of the emitter, we perform ultrafast spectral diffusion measurements that partially account for the coherence times. Our results provide important insight into the relaxation processes in quantum emitters in hBN which is mandatory to evaluate their applicability for quantum information processing.
Tawfik, S.A., Ali, S., Fronzi, M., Kianinia, M., Tran, T.T., Stampfl, C., Aharonovich, I., Toth, M. & Ford, M.J. 2017, 'First-principles investigation of quantum emission from hBN defects.', Nanoscale, vol. 9, no. 36, pp. 13575-13582.View/Download from: UTS OPUS or Publisher's site
Hexagonal boron nitride (hBN) has recently emerged as a fascinating platform for room-temperature quantum photonics due to the discovery of robust visible light single-photon emitters. In order to utilize these emitters, it is necessary to have a clear understanding of their atomic structure and the associated excitation processes that give rise to this single photon emission. Here, we performed density-functional theory (DFT) and constrained DFT calculations for a range of hBN point defects in order to identify potential emission candidates. By applying a number of criteria on the electronic structure of the ground state and the atomic structure of the excited states of the considered defects, and then calculating the Huang-Rhys (HR) factor, we found that the CBVN defect, in which a carbon atom substitutes a boron atom and the opposite nitrogen atom is removed, is a potential emission source with a HR factor of 1.66, in good agreement with the experimental HR factor. We calculated the photoluminescence (PL) line shape for this defect and found that it reproduces a number of key features in the experimental PL lineshape.
Tran, T.T., Wang, D., Xu, Z.-.Q., Yang, A., Toth, M., Odom, T.W. & Aharonovich, I. 2017, 'Deterministic Coupling of Quantum Emitters in 2D Materials to Plasmonic Nanocavity Arrays.', Nano Letters, vol. 17, no. 4, pp. 2634-2639.View/Download from: UTS OPUS or Publisher's site
Quantum emitters in two-dimensional materials are promising candidates for studies of light-matter interaction and next generation, integrated on-chip quantum nanophotonics. However, the realization of integrated nanophotonic systems requires the coupling of emitters to optical cavities and resonators. In this work, we demonstrate hybrid systems in which quantum emitters in 2D hexagonal boron nitride (hBN) are deterministically coupled to high-quality plasmonic nanocavity arrays. The plasmonic nanoparticle arrays offer a high-quality, low-loss cavity in the same spectral range as the quantum emitters in hBN. The coupled emitters exhibit enhanced emission rates and reduced fluorescence lifetimes, consistent with Purcell enhancement in the weak coupling regime. Our results provide the foundation for a versatile approach for achieving scalable, integrated hybrid systems based on low-loss plasmonic nanoparticle arrays and 2D materials.
Webb, J.R., Martin, A.A., Johnson, R.P., Joseph, M.B., Newton, M.E., Aharonovich, I., Toth, M. & Macpherson, J.V. 2017, 'Fabrication of a single sub-micron pore spanning a single crystal (100) diamond membrane and impact on particle translocation', Carbon, vol. 122, pp. 319-328.View/Download from: Publisher's site
© 2017 Elsevier Ltd The fabrication of sub-micron pores in single crystal diamond membranes, which span the entirety of the membrane, is described for the first time, and the translocation properties of polymeric particles through the pore investigated. The pores are produced using a combination of laser micromachining to form the membrane and electron beam induced etching to form the pore. Single crystal diamond as the membrane material, has the advantages of chemical stability and durability, does not hydrate and swell, has outstanding electrical properties that facilitate fast, low noise current-time measurements and is optically transparent for combined optical-conductance sensing. The resulting pores are characterized individually using both conductance measurements, employing a microcapillary electrochemical setup, and electron microscopy. Proof-of-concept experiments to sense charged polystyrene particles as they are electrophoretically driven through a single diamond pore are performed, and the impact of this new pore material on particle translocation is explored. These findings reveal the potential of diamond as a platform for pore-based sensing technologies and pave the way for the fabrication of single nanopores which span the entirety of a diamond membrane.
Zhou, Y., Rasmita, A., Li, K., Xiong, Q., Aharonovich, I. & Gao, W.-.B. 2017, 'Coherent control of a strongly driven silicon vacancy optical transition in diamond.', Nature Communications, vol. 8, pp. 1-8.View/Download from: UTS OPUS or Publisher's site
The ability to prepare, optically read out and coherently control single quantum states is a key requirement for quantum information processing. Optically active solid-state emitters have emerged as promising candidates with their prospects for on-chip integration as quantum nodes and sources of coherent photons connecting these nodes. Under a strongly driving resonant laser field, such quantum emitters can exhibit quantum behaviour such as Autler-Townes splitting and the Mollow triplet spectrum. Here we demonstrate coherent control of a strongly driven optical transition in silicon vacancy centre in diamond. Rapid optical detection of photons enabled the observation of time-resolved coherent Rabi oscillations and the Mollow triplet spectrum. Detection with a probing transition further confirmed Autler-Townes splitting generated by a strong laser field. The coherence time of the emitted photons is comparable to its lifetime and robust under a very strong driving field, which is promising for the generation of indistinguishable photons.
Wang, S., Clapper, A., Chen, P., Wang, L., Aharonovich, I., Jin, D. & Li, Q. 2017, 'Tuning Enhancement Efficiency of Multiple Emissive Centers in Graphene Quantum Dots by Core-Shell Plasmonic Nanoparticles.', The journal of physical chemistry letters, vol. 8, no. 22, pp. 5673-5679.View/Download from: Publisher's site
Graphene quantum dots (GQDs) are emerging luminescent nanomaterials for energy, bioimaging, and optoelectronic applications. However, unlike conventional fluorophores, GQDs contain multiple emissive centers that result in a complex interaction with external electromagnetic fields. Here we utilize core-shell plasmonic nanoparticles to simultaneously enhance and modulate the photoluminescence (PL) intensities and spectral profiles of GQDs. By analyzing the spectral profiles, we show that the emissive centers are highly influenced by the proximity to the metal particles. Under optimal spacer thickness of 25 nm, the overall PL displays a four-fold enhancement compared with a pristine GQD. However, detailed lifetime measurements indicate the presence of midgap states that act as the bottleneck for further enhancement. Our results offer new perspectives for fundamental understanding and new design of functional luminescent materials (e.g., GQDs, graphene oxide, carbon dots) for imaging, sensing, and light harvesting.
Tran, T.T., Choi, S., Scott, J.A., Xu, Z.Q., Zheng, C., Seniutinas, G., Bendavid, A., Fuhrer, M.S., Toth, M. & Aharonovich, I. 2017, 'Room-Temperature Single-Photon Emission from Oxidized Tungsten Disulfide Multilayers', Advanced Optical Materials, vol. 5, no. 5, pp. 1-5.View/Download from: UTS OPUS or Publisher's site
Robust quantum emitters fabricated by thermal oxidation of tungsten disulfide multilayers are reported. The emitters show robust, optically stable, linearly polarized luminescence at room temperature, can be modeled using a threelevel system, and exhibit moderate bunching. Overall, the results provide important insights into understanding of defect formation and quantum emitter activation in twodimensional materials.
Walia, S., Balendhran, S., Ahmed, T., Singh, M., El-Badawi, C., Brennan, M.D., Weerathunge, P., Karim, M.N., Rahman, F., Rassell, A., Duckworth, J., Ramanathan, R., Collis, G.E., Lobo, C.J., Toth, M., Kotsakidis, J.C., Weber, B., Fuhrer, M., Dominguez-Vera, J.M., Spencer, M.J.S., Aharonovich, I., Sriram, S., Bhaskaran, M. & Bansal, V. 2017, 'Ambient Protection of Few-Layer Black Phosphorus via Sequestration of Reactive Oxygen Species.', Advanced Materials, vol. 29, pp. 1-8.View/Download from: UTS OPUS or Publisher's site
Few-layer black phosphorous (BP) has emerged as a promising candidate for next-generation nanophotonic and nanoelectronic devices. However, rapid ambient degradation of mechanically exfoliated BP poses challenges in its practical deployment in scalable devices. To date, the strategies employed to protect BP have relied upon preventing its exposure to atmospheric conditions. Here, an approach that allows this sensitive material to remain stable without requiring its isolation from the ambient environment is reported. The method draws inspiration from the unique ability of biological systems to avoid photo-oxidative damage caused by reactive oxygen species. Since BP undergoes similar photo-oxidative degradation, imidazolium-based ionic liquids are employed as quenchers of these damaging species on the BP surface. This chemical sequestration strategy allows BP to remain stable for over 13 weeks, while retaining its key electronic characteristics. This study opens opportunities to practically implement BP and other environmentally sensitive 2D materials for electronic applications.
© 2016 Macmillan Publishers Limited, part of Springer Nature. Single-photon emitters play an important role in many leading quantum technologies. There is still no 'ideal' on-demand single-photon emitter, but a plethora of promising material systems have been developed, and several have transitioned from proof-of-concept to engineering efforts with steadily improving performance. Here, we review recent progress in the race towards true single-photon emitters required for a range of quantum information processing applications. We focus on solid-state systems including quantum dots, defects in solids, two-dimensional hosts and carbon nanotubes, as these are well positioned to benefit from recent breakthroughs in nanofabrication and materials growth techniques. We consider the main challenges and key advantages of each platform, with a focus on scalable on-chip integration and fabrication of identical sources on photonic circuits.
Li, K., Zhou, Y., Rasmita, A., Aharonovich, I. & Gao, W.B. 2016, 'Nonblinking Emitters with Nearly Lifetime-Limited Linewidths in CVD Nanodiamonds', Physical Review Applied, vol. 6, no. 2.View/Download from: Publisher's site
© 2016 American Physical Society. Near transform-limited single-photon sources are required for perfect photon indistinguishability in quantum networks. Having such sources in nanodiamonds is particularly important since it can enable engineering hybrid quantum-photonic systems. In this paper, we report the generation of optically stable, nearly transform-limited single silicon-vacancy emitters in nanodiamonds. Lines as narrow as 325 MHz are reported, which is close to the lifetime-limited linewidth (141 MHz). Moreover, the emitters exhibit minimal spectrum diffusion and high photostability, even if pumped well above saturation. Our results suggest that nanodiamonds can host color centers with superior properties suitable for hybrid photonic devices and quantum information.
Lienhard, B., Schröder, T., Mouradian, S., Dolde, F., Tran, T.T., Aharonovich, I. & Englund, D. 2016, 'Bright and photostable single-photon emitter in silicon carbide', Optica, vol. 3, no. 7, pp. 768-774.View/Download from: Publisher's site
© 2016 Optical Society of America. Single-photon sources are of paramount importance in quantum communication, quantum computation, and quantum metrology. In particular, there is great interest in realizing scalable solid-state platforms that can emit triggered photons on demand to achieve scalable nanophotonic networks. We report on a visible-spectrum single-photon emitter in 4H silicon carbide (SiC). The emitter is photostable at room and low temperatures, enabling photon counts per second in excess of 2 10 6 from unpatterned bulk SiC. It exists in two orthogonally polarized states, which have parallel absorption and emission dipole orientations. Low-temperature measurements reveal a narrow zero phonon line (linewidth < 0.1 nm) that accounts for > 30%of the total photoluminescence spectrum.
Stehlik, S., Ondic, L., Berhane, A.M., Aharonovich, I., Girard, H.A., Arnault, J.C. & Rezek, B. 2016, 'Photoluminescence of nanodiamonds influenced by charge transfer from silicon and metal substrates', Diamond and Related Materials, vol. 63, pp. 91-96.View/Download from: UTS OPUS or Publisher's site
© 2015 Elsevier B.V. All rights reserved. Photoluminescence of 5 nm detonation nanodiamonds (DNDs) is studied as a function of their surface treatment (hydrogenation/oxidation) and underlying substrate materials (silicon, gold, platinum, and nickel). The substrates affect DND photoluminescence emission spectrum and lifetime in the spectral range of 600-800 nm. The dependence is different for hydrogenated and oxidized DNDs. We attribute these effects to different electrostatic charging of DNDs on the substrates with different work functions (4.4 to 5.5 eV). We discuss the data based on naturally present NV centers, their phonon sideband, and surface-related non-radiative transitions.
Tran, T.T., Bray, K., Ford, M.J., Toth, M. & Aharonovich, I. 2016, 'Quantum emission from hexagonal boron nitride monolayers.', Nature nanotechnology, vol. 11, no. 1, pp. 37-41.View/Download from: UTS OPUS or Publisher's site
Artificial atomic systems in solids are widely considered the leading physical system for a variety of quantum technologies, including quantum communications, computing and metrology. To date, however, room-temperature quantum emitters have only been observed in wide-bandgap semiconductors such as diamond and silicon carbide, nanocrystal quantum dots, and most recently in carbon nanotubes. Single-photon emission from two-dimensional materials has been reported, but only at cryogenic temperatures. Here, we demonstrate room-temperature, polarized and ultrabright single-photon emission from a colour centre in two-dimensional hexagonal boron nitride. Density functional theory calculations indicate that vacancy-related defects are a probable source of the emission. Our results demonstrate the unprecedented potential of van der Waals crystals for large-scale nanophotonics and quantum information processing.
Tran, T.T., Zachreson, C., Berhane, A.M., Bray, K., Sandstrom, R.G., Li, L.H., Taniguchi, T., Watanabe, K., Aharonovich, I. & Toth, M. 2016, 'Quantum Emission from Defects in Single-Crystalline Hexagonal Boron Nitride', Physical Review Applied, vol. 5, no. 3.View/Download from: UTS OPUS or Publisher's site
© 2016 American Physical Society. Bulk hexagonal boron nitride (hBN) is a highly nonlinear natural hyperbolic material that attracts major attention in modern nanophotonics applications. However, studies of its optical properties in the visible part of the spectrum and quantum emitters hosted by bulk hBN have not been reported to date. In this work, we study the emission properties of hBN crystals in the red spectral range using sub-band-gap optical excitation. Quantum emission from defects is observed at room temperature and characterized in detail. Our results advance the use of hBN in quantum nanophotonics technologies and enhance our fundamental understanding of its optical properties.
Zhang, Y., Čejka, J., Lumpkin, G.R., Tran, T.T., Aharonovich, I., Karatchevtseva, I., Price, J.R., Scales, N. & Lu, K. 2016, 'Hydrothermal synthesis, structures and properties of two uranyl oxide hydroxyl hydrate phases with Co(II) or Ni(II) ions', New Journal of Chemistry, vol. 40, no. 6, pp. 5357-5363.View/Download from: Publisher's site
© 2016 The Royal Society of Chemistry and the Centre National de la Recherche Scientifique. Two new iso-structured uranyl oxide hydroxyl hydrate (UOH) phases with the incorporation of cobalt(ii) or nickel(ii) ions have been synthesised under hydrothermal conditions and structurally characterised. Both K 4 Co(OH) 3 (H 2 O) 9 [(UO 2 ) 12 (O) 7 (OH) 13 ] (1) and K 4 Ni(OH) 3 (H 2 O) 9 [(UO 2 ) 12 (O) 7 (OH) 13 ] (2) have two-dimensional (2D) polymeric uranyl oxohydroxyl layers with either potassium and hydroxyl cobalt(ii) (1) or potassium and hydroxyl nickel(ii) (2) ions between layers via uranyl-cation interactions. This work highlights the feasibility of making new UOH phases via a hydrothermal route at relatively higher solution pHs. It also demonstrates that other transition metal ions which are readily available in the environment may also be incorporated into such UOH phases during the natural weathering of uraninite as well as during the storage and disposal of spent nuclear fuels.
Zhang, Y., Clegg, J.K., Lu, K., Lumpkin, G.R., Tran, T.T., Aharonovich, I., Scales, N. & Li, F. 2016, 'Uranium(VI) hybrid materials with [(UO2)3(µ3-O)(µ2-OH)3]+as the sub–building unit via uranyl–cation interactions', ChemistrySelect, vol. 1, no. 1, pp. 7-12.View/Download from: UTS OPUS or Publisher's site
© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim The hydrothermal reaction of uranyl nitrate with 1,4-benzenedicarboxylic acid (H 2 bdc) in the presence of strontium or potassium hydroxides and nitrates afford the formation of two new uranyl hybrid materials featuring extensive uranyl-strontium or uranyl-potassium interactions with [(UO 2 ) 3 (µ 3 -O)(µ 2 -OH) 3 ] + as the sub-building unit. Sr 1.5 [(UO 2 ) 12 (O) 3 (OH) 13 (bdc) 4 ]6H 2 O (1) contains one-dimensional (1D) uranyl oxohydroxyl ribbons made of trinuclear pentagonal bipyramidal uranyl units. The ribbons are linked together via uranyl-strontium interactions to form 2D inorganic domains which are further connected through µ 4 -bdc anions forming a 3D hybrid structure. This is the first reported uranyl-strontium interaction in extended hybrid solid with the shortest Sr-O yl bond length of 2.596 (8) Å. K 3 [(UO 2 ) 12 (O) 3 (OH) 13 (bdc) 4 ]8H 2 O (2) has a similar 3D hybrid structure built up through extensive K-O yl interactions with the shortest K-O yl bond length of 2.620 (6) Å. Raman spectroscopy has confirmed the presence of oxo-bridging (UOU) vibrations. Thermal stabilities and photoluminescent properties are reported.
Zhang, Y., Karatchevtseva, I., Bhadbhade, M., Tran, T.T., Aharonovich, I., Fanna, D.J., Shepherd, N.D., Lu, K., Li, F. & Lumpkin, G.R. 2016, 'Solvothermal synthesis of uranium(VI) phases with aromatic carboxylate ligands: A dinuclear complex with 4-hydroxybenzoic acid and a 3D framework with terephthalic acid', Journal of Solid State Chemistry, vol. 234, pp. 22-28.View/Download from: UTS OPUS or Publisher's site
Crown Copyright © 2015 Published by Elsevier Inc. With the coordination of dimethylformamide (DMF), two new uranium(VI) complexes with either 4-hydroxybenzoic acid (H 2 phb) or terephthalic acid (H 2 tph) have been synthesized under solvothermal conditions and structurally characterized. [(UO 2 ) 2 (Hphb) 2 (phb)(DMF)(H 2 O) 3 ]4H 2 O (1) has a dinuclear structure constructed with both pentagonal and hexagonal bipyramidal uranium polyhedra linked through a 2 -bridging ligand via both chelating carboxylate arm and alcohol oxygen bonding, first observation of such a coordination mode of 4-hydroxybenzoate for 5 f ions. [(UO 2 )(tph)(DMF)] (2) has a three-dimensional (3D) framework built with pentagonal bipyramidal uranium polyhedra linked with 4 -terephthalate ligands. The 3D channeled structure is facilitated by the unique carboxylate bonding with nearly linear C-O-U angles and the coordination of DMF molecules. The presence of phb ligands in different coordination modes, uranyl ions in diverse environments and DMF in complex 1, and tph ligand, DMF and uranyl ion in complex 2 has been confirmed by Raman spectroscopy. In addition, their thermal stability and photoluminescence properties have been investigated.
Scajev, P., Malinauskas, T., Seniutinas, G., Arnold, M.D., Gentle, A., Aharonovich, I., Gervinskas, G., Michaux, P., Hartley, J.S., Mayes, E.L.H., Stoddart, P.R. & Juodkazis, S. 2016, 'Light-induced reflectivity transients in black-Si nanoneedles', SOLAR ENERGY MATERIALS AND SOLAR CELLS, vol. 144, pp. 221-227.View/Download from: UTS OPUS or Publisher's site
Bray, K., Sandstrom, R., Elbadawi, C., Fischer, M., Schreck, M., Shimoni, O., Lobo, C., Toth, M. & Aharonovich, I. 2016, 'Localization of Narrowband Single Photon Emitters in Nanodiamonds.', ACS applied materials & interfaces, vol. 8, no. 11, pp. 7590-7594.View/Download from: UTS OPUS or Publisher's site
Diamond nanocrystals that host room temperature narrowband single photon emitters are highly sought after for applications in nanophotonics and bioimaging. However, current understanding of the origin of these emitters is extremely limited. In this work, we demonstrate that the narrowband emitters are point defects localized at extended morphological defects in individual nanodiamonds. In particular, we show that nanocrystals with defects such as twin boundaries and secondary nucleation sites exhibit narrowband emission that is absent from pristine individual nanocrystals grown under the same conditions. Critically, we prove that the narrowband emission lines vanish when extended defects are removed deterministically using highly localized electron beam induced etching. Our results enhance the current understanding of single photon emitters in diamond and are directly relevant to fabrication of novel quantum optics devices and sensors.
Choi, S., Tran, T.T., Elbadawi, C., Lobo, C., Wang, X., Juodkazis, S., Seniutinas, G., Toth, M. & Aharonovich, I. 2016, 'Engineering and Localization of Quantum Emitters in Large Hexagonal Boron Nitride Layers', ACS APPLIED MATERIALS & INTERFACES, vol. 8, no. 43, pp. 29642-29648.View/Download from: Publisher's site
Elbadawi, C., Tran, T.T., Kolíbal, M., Šikola, T., Scott, J., Cai, Q., Li, L.H., Taniguchi, T., Watanabe, K., Toth, M., Aharonovich, I. & Lobo, C. 2016, 'Electron beam directed etching of hexagonal boron nitride.', Nanoscale, vol. 8, no. 36, pp. 16182-16186.View/Download from: UTS OPUS or Publisher's site
Hexagonal boron nitride (hBN) is a wide bandgap van der Waals material with unique optical properties that make it attractive for two dimensional (2D) photonic and optoelectronic devices. However, broad deployment and exploitation of hBN is limited by alack of suitable material and device processing and nano prototyping techniques. Here we present a high resolution, single step electron beam technique for chemical dry etching of hBN. Etching is achieved using H2O as a precursor gas, at both room temperature and elevated hBN temperatures. The technique enables damage-free, nano scale, iterative patterning of supported and suspended 2D hBN, thus opening the door to facile fabrication of hBN-based 2D heterostructures and devices.
Kianinia, M., Shimoni, O., Bendavid, A., Schell, A.W., Randolph, S.J., Toth, M., Aharonovich, I. & Lobo, C.J. 2016, 'Robust, directed assembly of fluorescent nanodiamonds.', Nanoscale, vol. 8, no. 42, pp. 18032-18037.View/Download from: UTS OPUS or Publisher's site
Arrays of fluorescent nanoparticles are highly sought after for applications in sensing, nanophotonics and quantum communications. Here we present a simple and robust method of assembling fluorescent nanodiamonds into macroscopic arrays. Remarkably, the yield of this directed assembly process is greater than 90% and the assembled patterns withstand ultra-sonication for more than three hours. The assembly process is based on covalent bonding of carboxyl to amine functional carbon seeds and is applicable to any material, and to non-planar surfaces. Our results pave the way to directed assembly of sensors and nanophotonics devices.
Scott, J.A., Totonjian, D., Martin, A.A., Tran, T.T., Fang, J., Toth, M., McDonagh, A.M., Aharonovich, I. & Lobo, C.J. 2016, 'Versatile method for template-free synthesis of single crystalline metal and metal alloy nanowires.', Nanoscale, vol. 8, no. 5, pp. 2804-2810.View/Download from: UTS OPUS or Publisher's site
Metal and metal alloy nanowires have applications ranging from spintronics to drug delivery, but high quality, high density single crystalline materials have been surprisingly difficult to fabricate. Here we report a versatile, template-free, self-assembly method for fabrication of single crystalline metal and metal alloy nanowires (Co, Ni, NiCo, CoFe, and NiFe) by reduction of metal nitride precursors formed in situ by reaction of metal salts with a nitrogen source. Thiol reduction of the metal nitrides to the metallic phase at 550-600 °C results in nanowire growth. In this process, sulfur acts as a uniaxial structure-directing agent, passivating the surface of the growing nanowires and preventing radial growth. The versatility of the method is demonstrated by achieving nanowire growth from gas-phase, solution-phase or a combination of gas- and solution-phase precursors. The fabrication method is suited to large-area CVD on a wide range of solid substrates.
Tran, T.T., Elbadawi, C., Totonjian, D., Lobo, C.J., Grosso, G., Moon, H., Englund, D.R., Ford, M.J., Aharonovich, I. & Toth, M. 2016, 'Robust Multicolor Single Photon Emission from Point Defects in Hexagonal Boron Nitride.', ACS nano, vol. 10, no. 8, pp. 7331-7338.View/Download from: UTS OPUS or Publisher's site
Hexagonal boron nitride (hBN) is an emerging two-dimensional material for quantum photonics owing to its large bandgap and hyperbolic properties. Here we report two approaches for engineering quantum emitters in hBN multilayers using either electron beam irradiation or annealing and characterize their photophysical properties. The defects exhibit a broad range of multicolor room-temperature single photon emissions across the visible and the near-infrared spectral ranges, narrow line widths of sub-10 nm at room temperature, and a short excited-state lifetime, and high brightness. We show that the emitters can be categorized into two general groups, but most likely possess similar crystallographic structure. Remarkably, the emitters are extremely robust and withstand aggressive annealing treatments in oxidizing and reducing environments. Our results constitute a step toward deterministic engineering of single emitters in 2D materials and hold great promise for the use of defects in boron nitride as sources for quantum information processing and nanophotonics.
Berhane, A.M., Choi, S., Kato, H., Makino, T., Mizuochi, N., Yamasaki, S. & Aharonovich, I. 2015, 'Electrical excitation of silicon-vacancy centers in single crystal diamond', Applied Physics Letters, vol. 106, no. 17.View/Download from: Publisher's site
Electrically driven emission from negatively charged silicon-vacancy (SiV)- centers in single crystal diamond is demonstrated. The SiV centers were generated using ion implantation into an i region of a p-i-n single crystal diamond diode. Both electroluminescence and the photoluminescence signals exhibit the typical emission that is attributed to the (SiV)- centers. Under forward and reversed biased PL measurements, no signal from the neutral (SiV)0 defect could be observed. The realization of electrically driven (SiV)- emission is promising for scalable nanophotonics devices employing color centers in single crystal diamond.
Bray, K., Previdi, R., Gibson, B.C., Shimoni, O. & Aharonovich, I. 2015, 'Enhanced photoluminescence from single nitrogen-vacancy defects in nanodiamonds coated with phenol-ionic complexes.', Nanoscale, vol. 7, no. 11, pp. 4869-4874.View/Download from: UTS OPUS or Publisher's site
Fluorescent nanodiamonds are attracting major attention in the field of bio-sensing and bio-labeling. In this work we demonstrate a robust approach to achieve an encapsulation of individual nanodiamonds with phenol-ionic complexes that enhance the photoluminescence from single nitrogen vacancy (NV) centers. We show that single NV centres in the coated nanodiamonds also exhibit shorter lifetimes, opening another channel for high resolution sensing. We propose that the nanodiamond encapsulation reduces the non-radiative decay pathways of the NV color centers. Our results provide a versatile and assessable way to enhance photoluminescence from nanodiamond defects that can be used in a variety of sensing and imaging applications.
Buividas, R., Aharonovich, I., Seniutinas, G., Wang, X.W., Rapp, L., Rode, A.V., Taniguchi, T. & Juodkazis, S. 2015, 'Photoluminescence from voids created by femtosecond-laser pulses inside cubic-BN', OPTICS LETTERS, vol. 40, no. 24, pp. 5711-5713.View/Download from: Publisher's site
The emerging field of nanophotonics initiated a dedicated study of single photon sources and optical resonators in new class of materials. One such material is zinc oxide (ZnO) that has been long considered only for classical light-emitting applications. However, it recently showed promise for quantum photonics technologies. In this review, we highlight the recent advances in studying single emitters in ZnO, engineering of optical cavities and practical nanophotonics devices including nanolasers and electrically triggered devices. We finalize with an outlook at this promising area, as well as provide perspectives and open questions in solid state nanophotonics employing ZnO.
Fang, J., Levchenko, I., Yan, W., Aharonovich, I., Aramesh, M., Prawer, S. & Ostrikov, K.K. 2015, 'Plasmonic Metamaterial Sensor with Ultra-High Sensitivity in the Visible Spectral Range', Advanced Optical Materials, vol. 3, no. 6, pp. 750-755.View/Download from: UTS OPUS or Publisher's site
A metamaterial-based plasmonic sensor composed of thin metal and polymer layers deposited on top of a highly ordered porous alumina exhibits a sensitivity of more than 4800 nm per refractive index unit in the visible spectral range. The device is robust, cheap, has a large functional area of about 2 cm2, and the overall transmission is tunable by varying the film thickness.
Martin, A.A., Bahm, A., Bishop, J., Aharonovich, I. & Toth, M. 2015, 'Dynamic Pattern Formation in Electron-Beam-Induced Etching.', Physical review letters, vol. 115, no. 25, p. 255501.View/Download from: UTS OPUS or Publisher's site
We report highly ordered topographic patterns that form on the surface of diamond, span multiple length scales, and have a symmetry controlled by the precursor gas species used in electron-beam-induced etching (EBIE). The pattern formation dynamics reveals an etch rate anisotropy and an electron energy transfer pathway that is overlooked by existing EBIE models. We, therefore, modify established theory such that it explains our results and remains universally applicable to EBIE. The patterns can be exploited in controlled wetting, optical structuring, and other emerging applications that require nano- and microscale surface texturing of a wide band-gap material.
Martin, A.A., Randolph, S., Botman, A., Toth, M. & Aharonovich, I. 2015, 'Maskless milling of diamond by a focused oxygen ion beam', SCIENTIFIC REPORTS, vol. 5.View/Download from: UTS OPUS or Publisher's site
Tran, T.T., Fang, J., Zhang, H., Rath, P., Bray, K., Sandstrom, R.G., Shimoni, O., Toth, M. & Aharonovich, I. 2015, 'Facile Self-Assembly of Quantum Plasmonic Circuit Components.', Advanced materials (Deerfield Beach, Fla.), vol. 27, no. 27, pp. 4048-4053.View/Download from: UTS OPUS or Publisher's site
A facile and cost-effective self-assembly route to engineering of vital quantum plasmonic circuit components is reported. By modifying the surface energy of silver nanowires, the position and density of attached nanodiamonds can be maneuvered leading to silver nanowire/nanodiamond(s) hybrid nanostructures. These structures exhibit strong plasmonic coupling effects and thus hold promise to serve as quantum plasmonic components.
Zhang, Y., Karatchevtseva, I., Price, J.R., Aharonovich, I., Kadi, F., Lumpkin, G.R. & Li, F. 2015, 'Uranium(vi) complexes with isonicotinic acid: From monomer to 2D polymer with unique U-N bonding', RSC Advances, vol. 5, no. 42, pp. 33249-33253.View/Download from: Publisher's site
© The Royal Society of Chemistry 2015. Two new uranium(vi) complexes with isonicotinic acid (HINT) have been synthesized and characterized. [(UO < inf > 2 < /inf > )(NO < inf > 3 < /inf > ) < inf > 2 < /inf > (HINT) < inf > 2 < /inf > ] (1) has a monomeric structure constructed of a hexagonal bipyramidal uranyl centre, two nitrate anions and two monodentate HINT in trans-positions. [(UO < inf > 2 < /inf > )(OH)(INT)] (2) has a two-dimensional (2D) polymeric structure constructed of uranyl hydroxyl 1D pillars and < inf > 3 < /inf > -bridging INT anions; the first observation of INT in < inf > 3 < /inf > -bridging mode for U(vi) ion via U-N bonding. Thermal analysis confirmed both complexes lost coordinated INT ligands followed by further decomposition to form U < inf > 3 < /inf > O < inf > 8 < /inf > . Raman spectroscopy has confirmed the presence of uranyl ion and INT ligand in both complexes as well as the existence of nitrate vibrations in 1 and hydroxyl vibrations in 2. Their photoluminescence properties have been investigated.
Choi, S., Berhane, A.M., Gentle, A., Ton-That, C., Phillips, M.R. & Aharonovich, I. 2015, 'Electroluminescence from Localized Defects in Zinc Oxide: Toward Electrically Driven Single Photon Sources at Room Temperature', ACS APPLIED MATERIALS & INTERFACES, vol. 7, no. 10, pp. 5619-5623.View/Download from: UTS OPUS or Publisher's site
Choi, S., Phillips, M.R., Aharonovich, I., Pornsuwan, S., Cowie, B.C.C. & Ton-That, C. 2015, 'Photophysics of Point Defects in ZnO Nanoparticles', ADVANCED OPTICAL MATERIALS, vol. 3, no. 6, pp. 821-827.View/Download from: UTS OPUS or Publisher's site
Fluorescent nanodiamonds (FNDs) are becoming a pivotal material in a variety of applications spanning sensing, bio-labeling and nanophotonics. The unique feature of these nanoparticles is their ability to host bright, optically active, photostable defects (color centers) that emit across the entire spectral range. In conjunction with their chemical stability and the relatively known carbon chemistry, nanodiamonds are becoming a key player in modern technologies. This brief review will highlight some of the recent advances of FNDs with an emphasis on nanophotonics. © 2014 The Japan Society of Applied Physics.
© 2014 Macmillan Publishers Limited. All rights reserved. Silicon is the material of choice for modern microelectronics, whereas diamond is a luxurious gem. Now, researchers have demonstrated that silicon impurities in diamond can generate indistinguishable single photons-a requirement for quantum photonics and computing.
The burgeoning field of nanophotonics has grown to be a major research area,
primarily because of the ability to control and manipulate single quantum
systems (emitters) and single photons on demand. For many years studying
nanophotonic phenomena was limited to traditional semiconductors (including
silicon and GaAs) and experiments were carried out predominantly at cryogenic
temperatures. In the last decade, however, diamond has emerged as a new
contender to study photonic phenomena at the nanoscale. Offering plethora of
quantum emitters that are optically active at room temperature and ambient
conditions, diamond has been exploited to demonstrate super-resolution
microscopy and realize entanglement, Purcell enhancement and other quantum and
classical nanophotonic effects. Elucidating the importance of diamond as a
material, this review will highlight the recent achievements in the field of
diamond nanophotonics, and convey a roadmap for future experiments and
Aharonovich, I., Magyar, A.P., Bracher, D., Lee, J.C. & Hu, E.L. 2014, 'High Quality SiC Microdisk Resonators fabricated from monolithic epilayer wafers', Applied Physics Letters, vol. 104, pp. 051109-1-051109 -3.View/Download from: UTS OPUS or Publisher's site
The exquisite mechanical properties of SiC have made it an important industrial material with applications in microelectromechanical devices and high power electronics. Recently, the optical properties of SiC have garnered attention for applications in photonics, quantum information, and spintronics. This work demonstrates the fabrication of microdisks formed from a p-N SiC epilayer material. The microdisk cavities fabricated from the SiC epilayer material exhibit quality factors of as high as 9200 and the approach is easily adaptable to the fabrication of SiC-based photonic crystals and other photonic and optomechanical devices.
Castelletto, S., Johnson, B.C., Zachreson, C., Beke, D., Balogh, I., Ohshima, T., Aharonovich, I. & Gali, A. 2014, 'Room Temperature Quantum Emission from Cubic Silicon Carbide Nanoparticles', ACS NANO, vol. 8, no. 8, pp. 7938-7947.View/Download from: UTS OPUS or Publisher's site
Lee, J.C., Bracher, D.O., Cui, S., Ohno, K., McLellan, C.A., Zhang, X., Andrich, P., Alemán, B., Russell, K.J., Magyar, A.P., Aharonovich, I., Bleszynski Jayich, A., Awschalom, D. & Hu, E.L. 2014, 'Deterministic coupling of delta-doped nitrogen vacancy centers to a nanobeam photonic crystal cavity', Applied Physics Letters, vol. 105, no. 26.View/Download from: UTS OPUS or Publisher's site
© 2014 AIP Publishing LLC. The negatively charged nitrogen vacancy center (NV) in diamond has generated significant interest as a platform for quantum information processing and sensing in the solid state. For most applications, high quality optical cavities are required to enhance the NV zero-phonon line (ZPL) emission. An outstanding challenge in maximizing the degree of NV-cavity coupling is the deterministic placement of NVs within the cavity. Here, we report photonic crystal nanobeam cavities coupled to NVs incorporated by a delta-doping technique that allows nanometer-scale vertical positioning of the emitters. We demonstrate cavities with Q up to 24 000 and mode volume V 0.47(/n) 3 as well as resonant enhancement of the ZPL of an NV ensemble with Purcell factor of 20. Our fabrication technique provides a first step towards deterministic NV-cavity coupling using spatial control of the emitters.
Magyar, A., Hu, W.H., Shanley, T., Flatte, M.E., Hu, E. & Aharonovich, I. 2014, 'Synthesis of Luminescent Eu defects in diamond', Nature Communications, vol. 5, pp. 1-6.View/Download from: UTS OPUS or Publisher's site
Lanthanides are vital components in lighting, imaging technologies and future quantum memory applications owing to their narrow optical transitions and long spin coherence times. Recently, diamond has become a pre-eminent platform for the realisation of many experiments in quantum information science. Here we demonstrate a promising approach to incorporate Eu ions into diamond, providing a means to harness the exceptional characteristics of both lanthanides and diamond in a single material. Polyelectrolytes are used to electrostatically assemble Eu(III) chelate molecules on diamond and subsequently chemical vapour deposition is employed for the diamond growth. Fluorescence measurements show that the Eu atoms retain the characteristic optical signature of Eu(III) upon incorporation into the diamond lattice. Computational modelling supports the experimental findings, corroborating that Eu(III) in diamond is a stable configuration. The formed defects demonstrate the outstanding chemical control over the incorporation of impurities into diamond enabled by the electrostatic assembly together with chemical vapour deposition growth.
Martin, A.A., Aharonovich, I. & Toth, M. 2014, 'Gas-Mediated Electron Beam Induced Etching - From Fundamental Physics to Device Fabrication', Microscopy and Microanalysis, vol. 20, no. S3, pp. 364-365.View/Download from: UTS OPUS or Publisher's site
Gas-mediated electron beam induced etching (EBIE) is a nanoscale, direct-write technique analogous to gas-assisted focused ion beam (FIB) milling. The main advantage of EBIE is the elimination of sputtering and ion implantation during processing as well as greater material selectivity . Here we discuss recent developments that expand the scope of EBIE applications in nanofabrication and defect generation analysis, and show advances in hardware that open the door for new studies in reaction kinetics using a scanning electron microscope (SEM).
Sandstrom, R.G., Shimoni, O., Martin, A.A. & Aharonovich, I. 2014, 'Study of narrowband single photon emitters in polycrystalline diamond films', APPLIED PHYSICS LETTERS, vol. 105, no. 18.View/Download from: UTS OPUS or Publisher's site
Shanley, T.W., Martin, A.A., Aharonovich, I. & Toth, M. 2014, 'Localized chemical switching of the charge state of nitrogen-vacancy luminescence centers in diamond', APPLIED PHYSICS LETTERS, vol. 105, no. 6.View/Download from: UTS OPUS or Publisher's site
Toth, M., Zachreson, C. & Aharonovich, I. 2014, 'Role of recombination pathway competition in spatially resolved cathodoluminescence spectroscopy', Applied Physics Letters, vol. 105, no. 24.View/Download from: UTS OPUS or Publisher's site
© 2014 AIP Publishing LLC. Cathodoluminescence (CL) analysis enables characterization of optoelectronic materials and devices with high spatial resolution. However, data interpretation is complicated by the competitive nature of the CL generation process. Specifically, spatially resolved CL profiles are affected by both CL center distributions, and by the unknown distributions of recombination centers that do not generate peaks in measured CL spectra. Here, we use depth-resolved CL to show that the contribution of the latter can be deduced and removed from spatially resolved CL data. The utility of this technique is demonstrated using CL depth profiles of color centers in diamond.
Woolf, A., Puchtler, T., Aharonovich, I., Zhu, T., Niu, N., Wang, D., Oliver, R. & Hu, E.L. 2014, 'Distinctive signature of indium gallium nitride quantum dot lasing in microdisk cavities', PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, vol. 111, no. 39, pp. 14042-14046.View/Download from: UTS OPUS or Publisher's site
Zachreson, C., Martin, A.A., Aharonovich, I. & Toth, M. 2014, 'Electron Beam Controlled Restructuring of Luminescence Centers in Polycrystalline Diamond', ACS APPLIED MATERIALS & INTERFACES, vol. 6, no. 13, pp. 10367-10372.View/Download from: UTS OPUS or Publisher's site
Zhang, H., Aharonovich, I., Glenn, D.R., Schalek, R., Magyar, A.P., Lichtman, J.W., Hu, E.L. & Walsworth, R.L. 2014, 'Silicon-vacancy color centers in nanodiamonds: Cathodoluminescence imaging markers in the near infrared', Small, vol. 10, no. 10, pp. 1908-1913.View/Download from: UTS OPUS or Publisher's site
Nanodiamonds doped with silicon-vacancy (Si-V) color centers are shown to be a promising candidate for cathodoluminescence (CL) imaging at the nanoscale, providing bright, non-bleaching, narrow-linewidth emission at wavelengths within the near-IR window of biological tissue. CL emission intensity from negative charge-state Si-V centers is greatly enhanced by increasing the nitrogen concentration during nanodiamond growth. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Castelletto, S., Bodrog, Z., Magyar, A.P., Gentle, A., Gali, A. & Aharonovich, I. 2014, 'Quantum-confined single photon emission at room temperature from SiC tetrapods', NANOSCALE, vol. 6, no. 17, pp. 10027-10032.View/Download from: UTS OPUS or Publisher's site
Choi, S., Johnson, B.C., Castelletto, S., Ton-That, C., Phillips, M.R. & Aharonovich, I. 2014, 'Single photon emission from ZnO nanoparticles', APPLIED PHYSICS LETTERS, vol. 104.View/Download from: UTS OPUS or Publisher's site
Room temperature single photon emitters are very important resources for photonics and emerging quantum technologies. In this work, we study single photon emission from defect centers in 20nm zinc oxide (ZnO) nanoparticles. The emitters exhibit bright broadband fluorescence in the red spectral range centered at 640nm with polarized excitation and emission. The studied emitters showed continuous blinking; however, bleaching can be suppressed using a polymethyl methacrylate coating. Furthermore, hydrogen termination increased the density of single photon emitters. Our results will contribute to the identification of quantum systems in ZnO. (C) 2014 AIP Publishing LLC.
Aharonovich, I., Lee, J.C., Magyar, A.P., Bracher, D.O. & Hu, E.L. 2013, 'Bottom-up engineering of diamond micro- and nano-structures', LASER & PHOTONICS REVIEWS, vol. 7, no. 5, pp. L61-L65.View/Download from: UTS OPUS or Publisher's site
Aharonovich, I., Woolf, A., Russell, K.J., Zhu, T., Niu, N., Kappers, M.J., Oliver, R.A. & Hu, E.L. 2013, 'Low threshold, room-temperature microdisk lasers in the blue spectral range', Applied Physics Letters, vol. 103, no. 2, pp. 1-4.View/Download from: UTS OPUS or Publisher's site
InGaN-based active layers within microcavity resonators offer the potential of low threshold lasers
in the blue spectral range. Here, we demonstrate optically pumped, room temperature lasing in high
quality factor GaN microdisk cavities, containing InGaN quantum dots (QDs) with thresholds as
low as 0.28 mJ/cm2
. The demonstration of lasing action from GaN microdisk cavities with QDs in
the active layer, provides a critical step for the nitrides in realizing low threshold photonic devices
with efficient coupling between QDs and an optical cavity
Kennard, J.E., Hadden, J.P., Marseglia, L., Aharonovich, I., Castelletto, S., Patton, B.R., Politi, A., Matthews, J.C.F., Sinclair, A.G., Gibson, B.C., Prawer, S., Rarity, J.G. & O'Brien, J.L. 2013, 'On-Chip Manipulation of Single Photons from a Diamond Defect', PHYSICAL REVIEW LETTERS, vol. 111, no. 21.View/Download from: UTS OPUS or Publisher's site
Lee, J., Magyar, A., Bracher, D., Aharonovich, I. & Hu, E. 2013, 'Fabrication Of Thin Diamond Membranes For Photonic Applications', Diamond and Related Materials, vol. 33, no. 1, pp. 45-48.View/Download from: UTS OPUS or Publisher's site
High quality, thin diamond membranes containing nitrogen-vacancy centers provide critical advantages in the fabrication of diamond-based structures for a variety of applications, including wide field magnetometry, photonics and biosensing. In this work we describe, in detail, the generation of thin, optically-active diamond membranes by means of ion implantation and overgrowth. To establish the suitability of our method for photonic applications, photonic crystal cavities with quality factor of 1000 are fabricated.
Recently, significant research efforts have been made to develop complex nanostructures to provide more sophisticated control over the optical and electronic properties of nanomaterials. However, there are only a handful of semiconductors that allow control over their geometry via simple chemical processes. Herein, we present a molecularly seeded synthesis of a complex nanostructure, SiC tetrapods, and report on their structural and optical properties. The SiC tetrapods exhibit narrow line width photoluminescence at wavelengths spanning the visible to near-infrared spectral range. Synthesized from low-toxicity, earth abundant elements, these tetrapods are a compelling replacement for technologically important quantum optical materials that frequently require toxic metals such as Cd and Se. This previously unknown geometry of SiC nanostructures is a compelling platform for biolabeling, sensing, spintronics, and optoelectronics.
Merson, T.D., Castelletto, S., Aharonovich, I., Turbic, A., Kilpatrick, T.J. & Turnley, A.M. 2013, 'Nanodiamonds with silicon vacancy defects for non-toxic photostable fluorescent labeling of neural precursor cells', Optics Letters, vol. 38, no. 20, pp. 4170-4173.View/Download from: UTS OPUS or Publisher's site
Nanodiamonds (NDs) containing silicon vacancy (SiV) defects were evaluated as a potential biomarker for the labeling and fluorescent imaging of neural precursor cells (NPCs). SiV-containing NDs were synthesized using chemical vapor deposition and silicon ion implantation. Spectrally, SiV-containing NDs exhibited extremely stable fluorescence and narrow bandwidth emission with an excellent signal to noise ratio exceeding that of NDs containing nitrogen-vacancy centers. NPCs labeled with NDs exhibited normal cell viability and proliferative properties consistent with biocompatibility. We conclude that SiV-containing NDs are a promising biomedical research tool for cellular labeling and optical imaging in stem cell research.
Choi, S., Ton-That, C., Phillips, M.R. & Aharonovich, I. 2013, 'Observation of whispering gallery modes from hexagonal ZnO microdisks using cathodoluminescence spectroscopy', APPLIED PHYSICS LETTERS, vol. 103, no. 17.View/Download from: UTS OPUS or Publisher's site
Aharonovich, I., Lee, J.C., Magyar, A.P., Buckley, B.B., Yale, C.G., Awschalom, D.D. & Hu, E.L. 2012, 'Homoepitaxial Growth of Single Crystal Diamond Membranes for Quantum Information Processing', ADVANCED MATERIALS, vol. 24, no. 10, pp. OP54-OP59.View/Download from: UTS OPUS or Publisher's site
Fang, J., Aharonovich, I., Leychenko, I., Ostrikov, K., Spizzirri, P.G., Rubanov, S. & Prawer, S. 2012, 'Plasma-enabled growth of single-crystalline SiC/AlSiC core-shell nanowires on porous alumina templates', Crystal Growth and Design, vol. 12, no. 6, pp. 2917-2922.View/Download from: UTS OPUS or Publisher's site
We report the catalyst-free synthesis of the arrays of core-shell, ultrathin, size-uniform SiC/AlSiC nanowires on the top of a periodic anodic aluminum oxide template. The nanowires were grown using an environmentally friendly, silane-free process by exp
Lee, J.C., Aharonovich, I., Magyar, A.P., Rol, F. & Hu, E.L. 2012, 'Coupling of silicon-vacancy centers to a single crystal diamond cavity', Optics Express, vol. 20, no. 8, pp. 8891-8897.View/Download from: UTS OPUS or Publisher's site
Optical coupling of an ensemble of silicon-vacancy (SiV) centers to single-crystal diamond microdisk cavities is demonstrated. The cavities are fabricated from a single-crystal diamond membrane generated by ion implantation and electrochemical liftoff fo
Muller, T., Aharonovich, I., Wang, Z., Yuan, X., Castelletto, S., Prawer, S. & Atarture, M. 2012, 'Phonon-induced dephasing of chromium color centers in diamond', Physical Review B, vol. 86, no. 19, p. 195210.View/Download from: UTS OPUS or Publisher's site
We report on the coherence properties of single photons from chromium-based color centers in diamond. We use field-correlation and spectral line-shape measurements to reveal the interplay between slow spectral wandering and fast dephasing mechanisms as a function of temperature. The zero-phonon transition frequency and its linewidth follow a power-law dependence on temperature, which is consistent with direct electronphonon coupling and phonon-modulated Coulomb coupling to nearby impurities, which are the predominant fast dephasing mechanisms for these centers. Further, the observed reduction in the quantum yield for photon emission as a function of temperature suggests the opening of additional nonradiative channels through thermal activation to higher-energy states and indicates a near-unity quantum efficiency at 4 K.
Niu, N., Liu, T.-.L., Aharonovich, I., Russell, K.J., Woolf, A., Sadler, T.C., El-Ella, H.A.R., Kappers, M.J., Oliver, R.A. & Hu, E.L. 2012, 'A full free spectral range tuning of p-i-n doped gallium nitride microdisk cavity', APPLIED PHYSICS LETTERS, vol. 101, no. 16.View/Download from: Publisher's site
Orwa, J.O., Ganesan, K., Newnham, J., Santori, C., Barclay, P., Fu, K.M., Beausoleil, R.G., Aharonovich, I., Fairchild, B.A., Olivero, P., Greentree, A.D. & Prawer, S. 2012, 'An upper limit on the lateral vacancy diffusion length in diamond', Diamond and Related Materials, vol. 24, no. 1, pp. 6-10.View/Download from: UTS OPUS or Publisher's site
Ion implantation is widely used to modify the structural, electrical and optical properties of materials. By appropriate masking, this technique can be used to define nano- and micro-structures. However, depending on the type of mask used, experiments have shown that vacancy-related substrate modification can be inferred tens of micrometers away from the edge of the mask used to define the implanted region. This could be due to fast diffusion of vacancies from the implanted area during annealing or to a geometric effect related to ion scattering around the mask edges. For quantum and single-atom devices, stray ion damage can be deleterious and must be minimized. In order to profile the distribution of implantation-induced damage, we have used the nitrogen-vacancy color center as a sensitive marker for vacancy concentration and distribution following MeV He ion implantation into diamond and annealing. Results show that helium atoms implanted through a mask clamped to the diamond surface are scattered underneath the mask to distances in the range of tens of micrometers from the mask edge. Implantation through a lithographically defined and deposited mask, with no spacing between the mask and the substrate, significantly reduces the scattering to = 5 µm but does not eliminate it. These scattering distances are much larger than the theoretically estimated vacancy diffusion distance of ~ 260 nm under similar conditions. This paper shows that diffusion, upon annealing, of vacancies created by ion implantation in diamond, is limited, and the appearance of vacancies many tens of micrometers from the edge of the mask is due to scattering effects
Aharonovich, I., Castelletto, S., Johnson, B.C., McCallum, J.C. & Prawer, S. 2011, 'Engineering chromium-related single photon emitters in single crystal diamonds', New Journal of Physics, vol. 13, p. 045015.View/Download from: UTS OPUS or Publisher's site
Color centers in diamond, as single photon emitters, are leading candidates for future quantum devices due to their room temperature operation and photostability. The recently discovered chromium-related centers are particularly attractive because they possess narrow bandwidth emission and a very short lifetime. In this paper, we investigate the fabrication methodologies for engineering these centers in monolithic diamond. We show that the emitters can be successfully fabricated by ion implantation of chromium in conjunction with oxygen or sulfur. Furthermore, our results indicate that the background nitrogen concentration is an important parameter, which governs the probability of success in generating these centers.
Aharonovich, I., Castelletto, S., Simpson, D.A., Su, C., Greentree, A.D. & Prawer, S. 2011, 'Diamond-based single-photon emitters', Reports on Progress in Physics, vol. 74.View/Download from: UTS OPUS or Publisher's site
The exploitation of emerging quantum technologies requires efficient fabrication of key building blocks. Sources of single photons are extremely important across many applications as they can serve as vectors for quantum informationthereby allowing long-range (perhaps even global-scale) quantum states to be made and manipulated for tasks such as quantum communication or distributed quantum computation. At the single-emitter level, quantum sources also afford new possibilities in terms of nanoscopy and bio-marking. Color centers in diamond are prominent candidates to generate and manipulate quantum states of light, as they are a photostable solid-state source of single photons at room temperature. In this review, we discuss the state of the art of diamond-based single-photon emitters and highlight their fabrication methodologies. We present the experimental techniques used to characterize the quantum emitters and discuss their photophysical properties. We outline a number of applications including quantum key distribution, bio-marking and sub-diffraction imaging, where diamond-based single emitters are playing a crucial role. We conclude with a discussion of the main challenges and perspectives for employing diamond emitters in quantum information processing.
Diamond, a material marvelled for its strength, beauty and perfection, was first used to polish stone axes in Neolithic times. This most ancient of materials is now being touted by many as the ideal platform for quantum-age technologies. In this Review, we describe how the properties of diamond match the requirements of the `second quantum revolution. We also discuss recent progress in the development of diamond and particularly diamond colour centres for transforming quantum information science into practical quantum information technology.
Aharonovich, I., Niu, N., Rol, F., Russell, K.J., Woolf, A., El-Ella, H.A.R., Kappers, M.J., Oliver, R.A. & Hu, E.L. 2011, 'Controlled tuning of whispering gallery modes of GaN/InGaN microdisk cavities', APPLIED PHYSICS LETTERS, vol. 99, no. 11.View/Download from: UTS OPUS or Publisher's site
Henderson, R., Gibson, B.C., Ebendorff-Heidepriem, H., Kuan, K., SA, V., Orwa, J.O., Aharonovich, I., Tomljenovic-Hanic, S., Greentree, A.D., Prawer, S. & Monro, T.M. 2011, 'Diamond in tellurite glass: a new medium for quantum information', Advanced Materials, vol. 23, no. 25, pp. 2806-2810.View/Download from: UTS OPUS or Publisher's site
Nitrogen-vacancy (NV) centers in diamond exhibit unique quantum properties. On page 2806, Matthew R. Henderson and co-workers describe integrated diamond nanocrystals containing NV centers with an optical medium, tellurite soft glass. The inside cover image shows an example of a confocal scan of an optical fiber drawn from this material, detecting the photoluminescence from NV centers, with a conceptual image of a scan in progress.
Magyar, A.P., Lee, J.C., Limarga, A.M., Aharonovich, I., Rol, F., Clarke, D.R., Huang, M. & Hu, E.L. 2011, 'Fabrication of thin, luminescent, single-crystal diamond membranes', APPLIED PHYSICS LETTERS, vol. 99, no. 8.View/Download from: UTS OPUS or Publisher's site
Muller, T., Aharonovich, I., Lombez, L., Alaverdyan, Y., Vamivakas, A.N., Castelletto, S., Jelezko, F., Wrachtrup, J., Prawer, S. & Atature, M. 2011, 'Wide-range electrical tunability of single-photon emission from chromium-based colour centres in diamond', New Journal of Physics, vol. 13.View/Download from: UTS OPUS or Publisher's site
We demonstrate electrical control of the single-photon emission spectrum from chromium-based colour centres implanted in monolithic diamond. Under an external electric field, the tunability range is typically three orders of magnitude larger than the radiative linewidth and at least one order of magnitude larger than the observed linewidth. The electric and magnetic field dependence of luminescence gives indications of the inherent symmetry, and we propose Cr-X or X-Cr-Y-type non-centrosymmetric atomic configurations as the most probable candidates for these centres.
Orwa, J.O., Santori, C., Fu, K.M., Gibson, B., Simpson, D., Aharonovich, I., Stacey, A., Cimmino, A., Balog, P., Markham, M., Twitchen, D., Greentree, A.D., Beausoleil, R.G. & Prawer, S. 2011, 'Engineering of nitrogen-vacancy color centers in high purity diamond by ion implantation and annealing', Journal of Applied Physics, vol. 109, no. 8, p. 083530.View/Download from: UTS OPUS or Publisher's site
The negatively-charged nitrogen-vacancy (NV) center is the most studied optical center in diamond and is very important for applications in quantum information science. Many proposals for integrating NV centers in quantum and sensing applications rely on their tailored fabrication in ultra pure host material. In this study, we use ion implantation to controllably introduce nitrogen into high purity, low nitrogen chemical vapor deposition diamond samples. The properties of the resulting NV centers are studied as a function of implantation temperature, annealing temperature, and implantation fluence. We compare the implanted NV centers with native NV centers present deep in the bulk of the as-grown samples. The results for implanted NV centers are promising but indicate, at this stage, that the deep native NV centers possess overall superior optical properties. In particular, the implanted NV centers obtained after annealing at 2000 !C under a stabilizing pressure of 8 GPa showed an ensemble linewidth of 0.17 nm compared to 0.61 nm after annealing at 1000 !C. Over the same temperature range, the ensemble NV"/NV0 ratio increased by a factor of #5, although this was accompanied by an overall decrease in the NV count.
Aharonovich, I. & Prawer, S. 2010, 'Fabrication strategies for diamond based ultra bright single photon sources', Diamond and Related Materials, vol. 19, pp. 729-733.View/Download from: UTS OPUS or Publisher's site
Color centers in diamond attract a major attention due to their potential use in quantum information processing. In this work several methodologies to fabricate diamond based single photon emitters are presented: Ion implantation of an impurity into diam
Aharonovich, I., Castelletto, S., Johnson, B.C., McCallum, J.C., Simpson, D.A., Greentree, A.D. & Prawer, S. 2010, 'Chromium single-photon emitters in diamond fabricated by ion implantation', Physical Review B, vol. 81, no. 12, pp. 1-4.View/Download from: UTS OPUS or Publisher's site
Controlled fabrication and identification of bright single-photon emitters is at the heart of quantum optics. Here we demonstrate controlled engineering of a chromium bright single-photon source in bulk diamond by ion implantation. The Cr center has full
Aharonovich, I., Castelletto, S., Simpson, D.A., Greentree, A.D. & Prawer, S. 2010, 'Photophysics of chromium-related diamond single-photon emitters', Physical Review A, vol. 81.View/Download from: UTS OPUS or Publisher's site
A detailed study of the photophysical properties of several chromium-related color centers produced within chemical vapor deposition diamond is presented. These emitters show narrow luminescence lines in the range of 740770 nm. Single-photon emission was veri?ed with continuous and pulsed excitation with detected emission rates at saturation in the range of (23)106 counts/s, while direct lifetime measurements reveal excited state lifetimes for the distinct centers ranging 114 ns. In addition, a number of quantum emitters demonstrate two-level behavior with no bunching present in the second-order correlation function. The three-level systems revealed typically photoluminescence lines with width half-maximum of ~4 nm while the two-level emitters have full width half-maximum of~10 nm at room temperature. In addition, the quantum ef?ciency of the two-level system was measured to be four times higher than that of the three-level system.
Castelletto, S., Aharonovich, I., Gibson, B.C., Johnson, B.C. & Prawer, S. 2010, 'Imaging and quantum-efficiency measurement of chromium emitters in diamond', Physical Review Letters, vol. 105, p. 217403.View/Download from: UTS OPUS or Publisher's site
We present direct imaging of the emission pattern of individual chromium-based single photon emitters in diamond and measure their quantum efficiency. By imaging the excited state transition dipole intensity distribution in the back focal plane of high numerical aperture objective, we determined that the emission dipole is oriented nearly orthogonal to the diamond-air interface. Employing ion implantation techniques, the emitters were engineered with various proximities from the diamond-air interface. By comparing the decay rates from the single chromium emitters at different depths in the diamond crystal, an average quantum efficiency of 28% was measured.
Greentree, A.D., Aharonovich, I., Castelletto, S., Doherty, W., McGuinness, L.P. & Simpson, D.A. 2010, '21st century applications of nanodiamonds', Optics & Photonics News, vol. 21, no. 9, pp. 20-25.View/Download from: Publisher's site
Diamond is taking on a new role as a versatile and practical platform for harnessing the new quantum physics. Here, we outline some of the biological and quantum applications of nanodiamonds and the central role of diamond color centers.
Orwa, J.O., Aharonovich, I., Jelezko, F., Balasubramanian, G., Balog, P., Markham, M., Twitchen, D.J., Greentree, A.D. & Prawer, S. 2010, 'Nickel related optical centres in diamond created by ion implantation', Journal of Applied Physics, vol. 107, no. 9, p. 093512.View/Download from: UTS OPUS or Publisher's site
Ni-related optical centres in diamond are promising as alternatives to the nitrogen vacancy (NV) centre for quantum applications and biomarking. In order to achieve the reliability and reproducibility required, a method for producing the Ni-related centres in a controllable manner needs to be established. In this study, we have attempted this control by implanting high purity CVD diamond samples with Ni and N followed by thermal annealing. Samples implanted with Ni show a new Ni-related PL peak centered at 711 nm and a well known doublet at 883/885 nm along with weak NV luminescence. The optical properties of the two Ni-related defects are investigated. In particular, an excited state lifetime of the 883/885 nm peak is measured to be 11.6 ns
Orwa, J.O., Greentree, A.D., Aharonovich, I., Alves, A.D., Van Donkelaar, J., Stacey, A. & Prawer, S. 2010, 'Fabrication of single optical centres in diamond - a review', Journal of Luminescence, vol. 130, no. 9, pp. 1646-1654.View/Download from: UTS OPUS or Publisher's site
Colour centres in diamond are rapidly becoming one of the leading platforms for solid-state quantum information processing applications. This is due in large part to the remarkable properties of the nitrogen-vacancy colour centre. From initial demonstrations of room-temperature single photon generation and spin single spin readout and quantum control, diamond nanocrystals are also finding application in magnetometry and biosensing. This review discusses the state of the art in the creation of isolated and small ensembles of optically active diamond defect centres, including nitrogen and nickelrelated centres.
Aharonovich, I., Castelletto, S., Simpson, D.A., Stacey, A., Mccallum, J., Greentree, A.D. & Prawer, S. 2009, 'Two-level ultrabright single photon emission from diamond nanocrystals', Nano Letters, vol. 9, no. 9, pp. 3191-3195.View/Download from: UTS OPUS or Publisher's site
The fabrication of stable ultrabright single photon sources operating at room temperature Is reported. The emitter is based on a color center within a diamond nanocrystal grown on a sapphire substrate by chemical vapor deposition method and exhibits a tw
Aharonovich, I., Santori, C., Fairchild, B.A., Orwa, J., Ganesan, K., Fu, K.C., Beausoleil, R.G., Greentree, A.D. & Prawer, S. 2009, 'Producing optimized ensembles of nitrogen-vacancy color centers for quantum information applications', Journal Of Applied Physics, vol. 106, no. 12.View/Download from: UTS OPUS or Publisher's site
Quantum information applications place stringent demands on the development of platforms that can host them. Color centers in diamond have been identified as important media for quantum information processing. Accordingly, the photoluminescence properties of nitrogen-vacancy N-V centers in diamond created by implantation and annealing are studied at cryogenic temperatures below 10 K. We examine high pressure high temperature and chemical vapor deposition synthetic diamonds with varying nitrogen concentration and present an accurate method to estimate the concentration of the N-V centers created by ion implantation. The ion irradiation route produced up to 6 ppm of optically active N-V centers, while nitrogen implantation yielded up to 3 ppm of optically active N-V with 8% conversion efficiency. However, a broadening of the N-V - zero phonon line was observed in all samples. © 200
Aharonovich, I., Zhou, C., Stacey, A., Orwa, J., Castelletto, S., Simpson, D., Greentree, A.D., Treussart, F., Roch, J. & Prawer, S. 2009, 'Enhanced single-photon emission in the near infrared from a diamond color center', Physical Review B, vol. 79, no. 23, pp. 0-0.View/Download from: UTS OPUS or Publisher's site
Individual color centers in diamond are promising for near-term quantum technologies including quantum key distribution and metrology. Here we show fabrication of an as-yet uncharacterized nickel-related complex in diamond which has photophysical propert
Siyushev, P., Jacques, V., Aharonovich, I., Kaiser, F., Muller, T., Lombez, L., Atature, M., Castelletto, S., Prawer, S., Jelezko, F. & Wrachtrup, J. 2009, 'Low-temperature optical characterization of a near-infrared single-photon emitter in nanodiamonds', New Journal of Physics, vol. 11.View/Download from: UTS OPUS or Publisher's site
In this paper, we study the optical properties of single defects emitting in the near infrared (NIR) in nanodiamonds at liquid helium temperature. The nanodiamonds are synthesized using a microwave chemical vapor deposition method followed by nickel implantation and annealing. We show that single defects exhibit several striking features at cryogenic temperature: the photoluminescence is strongly concentrated into a sharp zero-phonon line (ZPL) in the NIR, the radiative lifetime is in the nanosecond range and the emission is linearly polarized. The spectral stability of the defects is then investigated. An optical resonance linewidth of 4 GHz is measured using resonant excitation on the ZPL. Although Fourier-transform-limited emission is not achieved, our results show that it might be possible to use consecutive photons emitted in the NIR by single defects in diamond nanocrystals to perform two photon interference experiments, which are at the heart of linear quantum computing protocols.
Stacey, A., Aharonovich, I., Prawer, S. & Butler, J.E. 2009, 'Controlled synthesis of high quality micro/nano-diamonds by microwave plasma chemical vapor deposition', Diamond and Related Materials, vol. 18, no. 1, pp. 51-55.View/Download from: UTS OPUS or Publisher's site
Diamond containing engineered color centers is rapidly becoming a medium of choice for quantum information applications. Many of the dramatic recent results in this field have been demonstrated in diamond nano-crystals. Here we demonstrate controlled syn
Amorphous SiOx nanowires (NWs) were synthesized using laser ablation of silicon-containing targets. The influence of various parameters such as target composition, substrate type, substrate temperature and carrier gas on the growth process was studied. The NWs were characterized using high resolution scanning and transmission electron microscopes (HRSEM and HRTEM) with their attachments: electron dispersive spectroscopy (EDS) and energy electron loss spectroscopy (EELS). A metal catalyst was found essential for the NW growth. A growth temperature higher than 1000 ?C was necessary for the NW formation using an Ar-based carrier gas at 500 Torr. The use of Ar5%H2 instead of pure Ar resulted in a higher yield and longer NWs. Application of a diffusion barrier on top of the Si substrate guaranteed the availability of metal catalyst droplets on the surface, essential for the NW growth. Ni was found to be a better catalyst than Au in terms of the NW yield and length. Two alternative sequences for the evolution of the amorphous SiOx NWs were considered: (a) the formation of Si NWs first and their complete oxidation afterwards, which seems to be doubtful, (b) the direct formation of SiOx NWs, which is more likely to occur. The direct formation mechanism was proposed to advance in three stages: preferential adsorption of SiOx clusters on the catalyst surface first, a successive surface diffusion to the catalyst droplet lower hemisphere, and finally the formation and growth of the NW between the catalyst and the substrate.
Aharonovich, I., Zhou, C., Stacey, A., Treussart, F., Roch, J. & Prawer, S. 2008, 'Formation of color centers in nanodiamonds by plasma assisted diffusion of impurities from the growth substrate', Applied Physics Letters, vol. 93, no. 24, p. 243112.View/Download from: UTS OPUS or Publisher's site
A technique to create nickel-related single color centers in individual nanodiamonds is demonstrated. The method involves implantation of nickel ions into a substrate onto which the diamond nanocrystals are subsequently grown by chemical vapor deposition
Fu, K.-.M.C., Santori, C., Barclay, P.E., Aharonovich, I., Prawer, S., Meyer, N., Holm, A.M. & Beausoleil, R.G. 2008, 'Coupling of nitrogen-vacancy centers in diamond to a GaP waveguide', APPLIED PHYSICS LETTERS, vol. 93, no. 23.View/Download from: Publisher's site
Aharonovich, I., Lifshitz, Y. & Tamir, S. 2007, 'Growth mechanisms of amorphous SiOx nanowires', Applied Physics Letters, vol. 90, no. 26, p. 263109.
Amorphous SiOx nanowires (NWs) 10-50 nm thick and tens of microns long were grown by laser ablation of silicon containing targets onto different substrates held at elevated temperatures. The influence of the growth parameters on the NWs growth and struct
Aharonovich, I., Castelletto, S., Simpson, D.A., Greentree, A.D. & Prawer, S., 'Photophysics of novel diamond based single photon emitters', Phys Rev A 2010.View/Download from: UTS OPUS or Publisher's site
A detailed study of the photophysical properties of several novel color
centers in chemical vapor deposition diamond is presented. These emitters show
narrow luminescence lines in the near infra-red. Single photon emission was
verified with continuous and pulsed excitation with emission rates at
saturation in the MHz regime, whilst direct lifetime measurements reveal
excited state lifetimes ranging from 1-14 ns. In addition, a number of quantum
emitters demonstrate two level behavior with no bunching present in the second
order correlation function. An improved method of evaluating the quantum
efficiency through the direct measurement of the collection efficiency from two
level emitters is presented and discussed. \
Aharonovich, I., Zhou, C., Stacey, A., Orwa, J., Simpson, D., Greentree, A.D., Treussart, F., Roch, J.F. & Prawer, S., 'A new, enhanced diamond single photon emitter in the near infra-red'.View/Download from: UTS OPUS
Individual color centers in diamond are promising for near-term quantum
technologies including quantum key distribution and metrology. Here we show
fabrication of a new color center which has photophysical properties surpassing
those of the two main-stay centers, namely the nitrogen vacancy and NE8
centers. The new center is fabricated using focused ion beam implantation of
nickel into isolated chemical vapor deposited diamond micro-crystals. Room
temperature photoluminescence studies reveal a narrow emission in the near
infrared region centered at 768 nm with a lifetime as short as 2 ns. Its
focused ion beam compatibility opens the prospect to fabrication with nanometer
resolution and realization of integrated quantum photonic devices. Preliminary
investigations suggest that this center arises from an as-yet uncharacterized
Aharonovich, I. & Babinec, T. 2014, 'Single Color Centers in Diamond: Materials, Devices, and Applications' in Sarin, V.K. (ed), Comprehensive Hard Materials, Elsevier Ltd., pp. 469-491.View/Download from: UTS OPUS or Publisher's site
Photonic technologies play key roles in twenty-first century technologies. In addition to their traditional optical communications, quantum photonics, which relies on single photon emitters, offers new approaches to information processing. In this chapter, we discuss the photophysical properties and applications of single defects in diamond-also known as color centers. Although the focus will be on one particular emitter-the nitrogen-vacancy center, other defects will be mentioned and reviewed. Promising applications, namely, photonic devices and magnetometry, will be discussed in more detail, highlighting the recent literature. Finally, an outlook for diamond photonics will be presented. © 2014 Elsevier Ltd. All rights reserved.
Aharonovich, I. & Prawer, S. 2014, 'Promising directions in diamond technologies for quantum information processing (QIP) and sensing' in Quantum Information Processing with Diamond: Principles and Applications, Elsevier, pp. 307-317.View/Download from: UTS OPUS or Publisher's site
© 2014 Elsevier Ltd. All rights reserved. This final chapter summarizes some of the emerging topics in the usage of diamond for quantum information processing. Practical applications include biosensing and bioimaging using colour centres in diamond, as well as pathways towards integrated quantum photonics using diamond as a platform. On the other hand, challenges will be discussed, including surface terminations and engineering new, superior optically active defects. Finally, we discuss the outlook for the field of quantum information processing (QIP) with diamond.
Aharonovich, I. 2017, 'Quantum emitters in flatland', Optics InfoBase Conference Papers.
We demonstrate first room temperature, and ultrabright single photon emission from a color center in two-dimensional multilayer hexagonal boron nitride. Density Functional Theory calculations indicate that vacancy-related centers are a likely source of the emission. © 2017 OSA.
Grosso, G., Moon, H., Lienhard, B., Ali, S., Furchi, M.M., Walsh, M., Efetov, D.K., Jarillo-Herrero, P., Ford, M.J., Aharonovich, I. & Englund, D. 2017, 'Tunable quantum emission from atomic defects in hexagonal boron nitride', Optics InfoBase Conference Papers.View/Download from: Publisher's site
© 2017 OSA. We demonstrate that strain control of exfoliated hexagonal boron nitride allows spectral tuning of single photon emitters over 6 meV. We propose a material processing that sharply improves the single-photon purity with g (2) (0) = 0.077, and brightness with emission rate exceeding 10 7 counts/sec at saturation.
Schell, A.W., Takashima, H., Tran, T.T., Aharonovich, I. & Takeuchi, S. 2017, 'Spectroscopy of single quantum emitters in hexagonal boron nitride using linear and non-linear excitation', 2017 Conference on Lasers and Electro-Optics, CLEO 2017 - Proceedings, pp. 1-2.View/Download from: Publisher's site
© 2017 IEEE. Excitation of single photon emitters via a two-photon process can be employed for high resolution imaging and has applications in quantum optics. Here, we present one- and two-photon excitation of single defects in hexagonal boron.
Schell, A.W., Trong, T.T., Aharonovich, I., Takashima, H. & Takeuchi, S. 2017, 'Efficient extraction of photons from a single defect in hBN using a nanofiber', QUANTUM SENSING AND NANO ELECTRONICS AND PHOTONICS XIV, Conference on Quantum Sensing and Nano Electronics and Photonics XIV, SPIE-INT SOC OPTICAL ENGINEERING, San Francisco, CA.View/Download from: Publisher's site
Toan, T.T., Elbadawi, C., Totonjian, D., Lobo, C.J., Grosso, G., Moon, H., Englund, D.R., Ford, M.J., Aharonovich, I. & Toth, M. 2017, 'Robust Multicolor Single Photon Emission from Point Defects in Hexagonal Boron Nitride', 2017 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO), Conference on Lasers and Electro-Optics (CLEO), IEEE, San Jose, CA.
Aharonovich, I., Bray, K. & Shimoni, O. 2016, 'Florescent Nanodiamonds for Biomedical Applications', 2016 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO), Conference on Lasers and Electro-Optics (CLEO), IEEE, San Jose, CA.
Berhane, A.M., Choi, S., Kato, H., Makino, T., Mizuochi, N., Yamasaki, S., Toth, M. & Aharonovich, I. 2016, 'Defect luminescence in diamond and GaN: Towards single photon emitting devices', 2016 Conference on Lasers and Electro-Optics, CLEO 2016.View/Download from: UTS OPUS
½ 2016 OSA. Narrow band single photon emitters in diamond and gallium nitride are investigated. The work provides foundation towards electrically driven sources at room temperature that are important prerequisites for solid state quantum technologies.
© 2016 OSA.We demonstrate first room temperature, and ultrabright single photon emission from a color center in two-dimensional multilayer hexagonal boron nitride. Density Functional Theory calculations indicate that vacancy-related centers are a likely source of the emission.
Elbadawi, C., Tran, T.T., Shimoni, O., Totonjian, D., Lobo, C.J., Grosso, G., Moon, H., Englund, D.R., Ford, M.J., Aharonovich, I. & Toth, M. 2016, 'Ultra-bright emission from hexagonal boron nitride defects as a new platform for bio-imaging and bio-labelling', Proceedings of SPIE - The International Society for Optical Engineering.View/Download from: UTS OPUS or Publisher's site
© 2016 SPIE. Bio-imaging requires robust ultra-bright probes without causing any toxicity to the cellular environment, maintain their stability and are chemically inert. In this work we present hexagonal boron nitride (hBN) nanoflakes which exhibit narrowband ultra-bright single photon emitters1. The emitters are optically stable at room temperature and under ambient environment. hBN has also been noted to be noncytotoxic and seen significant advances in functionalization with biomolecules2,3. We further demonstrate two methods of engineering this new range of extremely robust multicolour emitters across the visible and near infrared spectral ranges for large scale sensing and biolabeling applications.
Toth, M., Martin, A.A., Shanley, T.W. & Aharonovich, I. 2014, 'Direct-write electron beam fabrication of optically active diamond nanostructures', 2014 Conference on Optoelectronic and Microelectronic Materials and Devices, COMMAD 2014, Conference on Optoelectronic and Microelectronic Materials and Devices, IEEE, Perth, Western Australia, Australia, pp. 6-10.View/Download from: UTS OPUS or Publisher's site
© 2014 IEEE. Controlled fabrication of semiconductor nanostructures is a prerequisite step in the engineering of next generation photonic and optoelectronic devices. Here we describe two advances in electron beam processing of single crystal diamond: (i) chemical dry etching of optically active nanostructures, and (ii) chemical switching of the charge state of nitrogen-vacancy centers by surface fluorination. Etching and fluorination are realized by irradiating diamond by kiloelectronvolt electrons at room temperature in the presence of H 2 O and NF 3 vapor, respectively. The techniques do not generate defects that quench luminescence, thereby enabling the fabrication and editing of optically active nanostructures and diamond-based devices.
Lobo, C.J., Martin, A.A., Elbadawi, C., Bishop, J., Aharonovich, I. & Toth, M. 2014, 'Gas-mediated charged particle beam processing of nanostructured materials', Proceedings of SPIE - The International Society for Optical Engineering, The International Society for Optical Engineering Conference, SPIE-INT SOC OPTICAL ENGINEERING, San Francisco, CA.View/Download from: UTS OPUS or Publisher's site
Gas mediated processing under a charged particle (electron or ion) beam enables direct-write, high resolution surface functionalization, chemical dry etching and chemical vapor deposition of a wide range of materials including catalytic metals, optoelectronic grade semiconductors and oxides. Here we highlight three recent developments of particular interest to the optical materials and nanofabrication communities: fabrication of self-supporting, three dimensional, fluorescent diamond nanostructures, electron beam induced deposition (EBID) of high purity materials via activated chemisorption, and post-growth purification of nanocrystalline EBID-grown platinum suitable for catalysis applications. © 2014 SPIE.
Castelletto, S., Johnson, B.C., Aharonovich, I. & Parker, A. 2013, 'Fluorescent emission in different silicon carbide polytypes', Proceedings of SPIE - The International Society for Optical Engineering, Conference on Micro/Nano Materials, Devices, and Systems, SPIE, Australia.View/Download from: UTS OPUS or Publisher's site
Silicon carbide (SiC) is a widely used material in several industrial applications such as high power electronics, light emitting diodes, and in research application such as photo-voltaic and quantum technologies. As nanoparticles it can be synthetised in many sizes and different polytypes from 200 nm down to 1 nm. In the form of quantum dots they are used as optical biomarkers, and their emission, occurring from the blue to the orange spectral region, is based on quantum confinement effect. In this work we report on emission in the red and near infrared in different SiC polytypes, specifically in 4H, 6H and 3C. In 4H SiC the red visible emission yielded non classical light attributed to an intrinsic defect, identified as a carbon-antisite vacancy pair. Similar spectral emission was observed in 3C SiC bulk and nanoparticles, also yielding very bright single photon emission. Emission in the far red has been observed in homogeneous hetero-structure in SiC tetrapods. © 2013 Copyright SPIE.
Greentree, A.D., Henderson, M.R., Gibson, B.C., Ebendorff-Heidepriem, H., Kuan, K., Afshar, V.S., Orwa, J.O., Aharonovich, I., Karle, T.J., Tomljenovic-Hanic, S., Prawer, S. & Monro, T.M. 2012, 'Diamond in glass, a new platform for quantum photonics', 2012 Conference on Lasers and Electro-Optics, CLEO 2012, Conference on Lasers and Electro-Optics, IEEE, San Jose, CA, USA.View/Download from: Publisher's site
Diamond color centers represent one of the most important frontiers for room-temperature solid-state quantum devices. Here we show the incorporation of fluorescent diamond nanoparticles into tellurite glass optical fibers. This system offers a new platform for quantum sensing and robust single photon collection and distribution. © 2012 OSA.
Greentree, A.D., Henderson, M.R., Gibson, B.C., Ebendorff-Heidepriem, H., Kuan, K., Afshar, V.S., Orwa, J.O., Aharonovich, I., Karle, T.J., Tomljenovic-Hanic, S., Prawer, S. & Monro, T.M. 2012, 'Diamond in glass, a new platform for quantum photonics', 2012 Conference on Lasers and Electro-Optics, CLEO 2012.
Diamond color centers represent one of the most important frontiers for room-temperature solid-state quantum devices. Here we show the incorporation of fluorescent diamond nanoparticles into tellurite glass optical fibers. This system offers a new platform for quantum sensing and robust single photon collection and distribution. © 2012 OSA.
Aharonovich, I., Castelletto, S. & Prawer, S. 2011, 'Novel single photon emitters based on color centers in diamond', AIP Conference Proceedings, International Conference on the Physics of Semiconductors (ICPS), pp. 997-998.View/Download from: UTS OPUS or Publisher's site
Single photon emitters are core components of quantum technologies. In this work new family of emitters based on chromium impurities in diamond is presented. The emitters can be fabricated by ion implantation of chromium into bulk diamond or incorporated during the growth of diamond nanocrystals. The remarkable photo-physical properties of these emitters include room temperature operation, narrow photoluminescence (PL) in the near infra red and ultra bright, fully polarized photon emission with count rate of 3.210 6 counts/s. These photo physical properties make the Cr centers ideal for quantum information processing, metrology, and cellular bio markers applications. © 2011 American Institute of Physics.
Gibson, B.C., Castelletto, S., Karle, T.J., Tomljenovic-Hanic, S., Aharonovich, I., Johnson, B.C., Orwa, J., Henderson, M.R., Ebendorff-Heidepriem, H., Kuan, K., Afshar, S.V., Monro, T.M., Greentree, A.D. & Prawer, S. 2011, 'Towards hybrid diamond optical devices', 2011 13th International Conference on Transparent Optical Networks, International Conference on Transparent Optical Networks, IEEE, Stockholm, Sweden.View/Download from: UTS OPUS or Publisher's site
Diamond is emerging as an optical supermaterial, due to its wide transparency bandwidth, excellent thermooptic properties and most notably its stable , large dipole moment, room temperature, single photon emitting colour centres. In this paper we present recent progress in the characterization of non radiative and radiative decay in single impurities and the fabrication of hybrid diamond-tellurite optical structures First, we present direct imaging of the emission pattern of individual ion implanted chromium-based single photon emitters in diamond and measure their quantum efficiency. By comparing the decay rates from the single chromium emitters at different depths in the diamond crystal, we measured an average quantum efficiency of 28%. Second, a hybrid approach involving a soft glass tellurite host material has been introduced, allowing nitrogen-vacancy (NV-) diamond emitters to be built into an optical fibre. The potential of integrating Cr-related centres in hybrid optical structures is also discussed. © 2011 IEEE.
Gibson, B.C., Henderson, M.R., Ebendorff-Heidepriem, H., Kuan, K., Afshar, V.S., Orwa, J.O., Aharonovich, I., Tomljenovic-Hanic, S., Prawer, S., Monro, T.M. & Greentree, A.D. 2011, 'Single photon emission from nanodiamond in tellurite glass', 2011 Int. Quantum Electron. Conf., IQEC 2011 and Conf. Lasers and Electro-Optics, CLEO Pacific Rim 2011 Incorporating the Australasian Conf. Optics, Lasers and Spectroscopy and the Australian Conf., pp. 721-722.View/Download from: Publisher's site
We demonstrate single photon emission from nanodiamond containing isolated single nitrogen-vacancy quantum emitters, embedded within tellurite glass optical fibres. This hybrid diamond-glass material presents a platform for next generation quantum photonics applications. © 2011 IEEE.
Gibson, B.C., Henderson, M.R., Ebendorff-Heidepriem, H., Kuan, K., Afshar, V.S., Orwa, J.O., Aharonovich, I., Tomljenovic-Hanic, S., Prawer, S., Monro, T.M. & Greentree, A.D. 2011, 'Single photon emission from nanodiamond in tellurite glass', 2011 Int. Quantum Electron. Conf., IQEC 2011 and Conf. Lasers and Electro-Optics, CLEO Pacific Rim 2011 Incorporating the Australasian Conf. Optics, Lasers and Spectroscopy and the Australian Conf., pp. 721-722.View/Download from: Publisher's site
We demonstrate single photon emission from nanodiamond containing isolated single nitrogen-vacancy quantum emitters, embedded within tellurite glass optical fibres. This hybrid diamond-glass material presents a platform for next generation quantum photonics applications. © 2011 IEEE.
Lee, J.C., Magyar, A., Aharonovich, I. & Hu, E.L. 2011, 'Fabrication of diamond microcavities for quantum information processing', Optics InfoBase Conference Papers, pp. 1100-1102.
The realization of quantum information processing requires sophisticated fabrication methodologies of its constituents. In this work we demonstrate the fabrication of micron size diamond microdisks from single crystal diamond. Photoluminescence measurements confirm the presence of nitrogen vacancy centers and show the propagation of whispering gallery modes. Such structures are promising for the realization of diamond integrated quantum photonics devices.© 2011 AOS.
Castelletto, S., Aharonovich, I., Su, C.H. & Prawer, S. 2010, 'Impurities in diamond- a new revival for quantum optics', QUANTUM COMMUNICATIONS AND QUANTUM IMAGING VIII.View/Download from: Publisher's site
Tomljenovic-Hanic, S., Aharonovich, I., Castelleto, S., Fairchild, B.A., Ganesan, K., Gibson, B.C., Greentree, A.D., Orwa, J., Rubanov, S., Simpson, D.A., Stacey, A. & Prawer, S. 2010, 'Towards all-diamond optical devices', 2010 12th International Conference on Transparent Optical Networks, ICTON 2010, 2010 12th International Conference on Transparent Optical Networks, IEEE, Munich, Germany.View/Download from: UTS OPUS or Publisher's site
Diamond is a unique material, with a host of attributes that seem to favour is as a platform for solid-state optical approaches to quantum information processing. Amongst the many outstanding properties of diamond, the most important for these applications are that it posses the largest transparency window in the visible regime, has the highest thermal conductivity, and most importantly, hosts a large number of high dipole moment colour centres. In this paper we give an overview of the fabrication and characterisation of diamond-based optical devices at the University of Melbourne. © 2010 IEEE.
Fu, K.-.M.C., Santori, C., Barclay, P.E., Meyer, N., Holm, A.M., Aharonovich, I., Prawer, S. & Beausoleil, R.G. 2009, 'Photonic structures for QIP in diamond', ADVANCED OPTICAL CONCEPTS IN QUANTUM COMPUTING, MEMORY, AND COMMUNICATION II.View/Download from: Publisher's site
Fu, K.-.M.C., Santori, C., Barclay, P.E., Meyer, N., Holm, A.M., Aharonovich, I., Prawer, S., Beausoleil, R.G. & IEEE 2009, 'Optical coupling of nitrogen-vacancy centers in diamond to GaP waveguides', 2009 CONFERENCE ON LASERS AND ELECTRO-OPTICS AND QUANTUM ELECTRONICS AND LASER SCIENCE CONFERENCE (CLEO/QELS 2009), VOLS 1-5, pp. 2050-2051.
Fu, K.M.C., Santori, C., Barclay, P.E., Meyer, N., Holm, A.M., Aharonovich, I., Prawer, S. & Beausoleil, R.G. 2009, 'Optical coupling of nitrogen-vacancy centers in diamond to GaP waveguides', 2009 Conference on Lasers and Electro-Optics and 2009 Conference on Quantum Electronics and Laser Science Conference, CLEO/QELS 2009.
In this work NV coupling to GaP waveguides on a diamond surface is demonstrated. The NV-waveguide coupling strength and waveguide loss are measured. This approach may be useful for NV-based quantum information processing. © 2008 Optical Society of America.
Recent advances in focused ion beam technology have enabled high-resolution,
direct-write nanofabrication using light ions. Studies with light ions to date
have, however, focused on milling of materials where sub-surface ion beam
damage does not inhibit device performance. Here we report on direct-write
milling of single crystal diamond using a focused beam of oxygen ions. Material
quality is assessed by Raman and luminescence analysis, and reveals that the
damage layer generated by oxygen ions can be removed by nonintrusive
post-processing methods such as localised electron beam induced chemical