Trycz, A, Regan, B, Kianinia, M, Bray, K, Toth, M & Aharonovich, I 2019, 'Bottom up engineering of single crystal diamond membranes with germanium vacancy color centers', OPTICAL MATERIALS EXPRESS, vol. 9, no. 12, pp. 4708-4715.View/Download from: Publisher's site
Häußler, S, Benedikter, J, Bray, K, Regan, B, Dietrich, A, Twamley, J, Aharonovich, I, Hunger, D & Kubanek, A 2019, 'Diamond photonics platform based on silicon vacancy centers in a single-crystal diamond membrane and a fiber cavity', Physical Review B, vol. 99, no. 16.View/Download from: Publisher's site
© 2019 American Physical Society. We realize a potential platform for an efficient spin-photon interface, namely negatively-charged silicon-vacancy centers in a diamond membrane coupled to the mode of a fully-tunable, fiber-based, optical resonator. We demonstrate that introducing the thin (∼200nm), single crystal diamond membrane into the mode of the resonator does not change the cavity properties, which is one of the crucial points for an efficient spin-photon interface. In particular, we observe constantly high Finesse values of up to 3000 and a linear dispersion in the presence of the membrane. We observe cavity-coupled fluorescence from an ensemble of SiV- centers with an enhancement factor of ∼1.9. Furthermore from our investigations we extract the ensemble absorption and extrapolate an absorption cross section of (2.9±2)×10-12cm2 for a single SiV- center, much higher than previously reported.
Previdi, R, Levchenko, I, Arnold, M, Gali, M, Bazaka, K, Xu, S, Ostrikov, K, Bray, K, Jin, D & Fang, J 2019, 'Plasmonic platform based on nanoporous alumina membranes: order control via self-assembly', Journal of Materials Chemistry A, vol. 7, no. 16, pp. 9565-9577.View/Download from: Publisher's site
© The Royal Society of Chemistry. A novel approach to significantly enhance and comprehensively assess the level of nanochannel ordering in self-assembled nanoporous membranes is proposed and tested. An advanced technique based on a two-step anodization and two-step chemical treatment was used to prepare the perfect through membranes by opening channels from the bottom via electrochemical enlargement, and chemical removal of a residual metal and barrier alumina layer. The influence of the process parameters on the self-assembled ordering was studied, and various methods of order assessment were proposed and tested, such as distributions of equivalent disc radii, 2D Fourier transformations, autocorrelation, Hough transformations, Minkowski connectivity, and distributions of nanochannel centre positions. We have demonstrated that self-assembled ordering in nanoscaled membranes could be efficiently tuned by the process parameters, and different assessment methods should be used to comprehensively characterize the order of nanochannels in the nanoporous membranes. To demonstrate the potential of this technique, we show simulations of the narrowing of plasmon spectra in these materials. The proposed fabrication and assessment methods could be used to drastically enhance the properties of nanoporous membranes for nanoelectronics, filters, sensors, bio-active devices and other advanced emerging applications. Finally, our approach could be used for enhancing and tailoring other self-assembled systems and devices of considerable complexity.
Bray, K, Kato, H, Previdi, R, Sandstrom, R, Ganesan, K, Ogura, M, Makino, T, Yamasaki, S, Magyar, AP, 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 μm2 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.
Bray, K, Regan, B, Trycz, A, Previdi, R, Seniutinas, G, Ganesan, K, Kianinia, M, Kim, S & Aharonovich, I 2018, 'Single Crystal Diamond Membranes and Photonic Resonators Containing Germanium Vacancy Color Centers', ACS Photonics, vol. 5, no. 12, pp. 4817-4822.View/Download from: Publisher's site
Copyright © 2018 American Chemical Society. Single crystal diamond membranes that host optically active emitters are highly attractive components for integrated quantum nanophotonics. In this work we demonstrate bottom-up synthesis of single crystal diamond membranes containing germanium vacancy (GeV) color centers. We employ a lift-off technique to generate the membranes and perform chemical vapor deposition in the presence of a germanium source to realize the in situ doping. Finally, we show that these membranes are suitable for engineering of photonic resonators such as microdisk cavities with quality factors of ∼1500. The robust and scalable approach to engineer single crystal diamond membranes containing emerging color centers is a promising pathway for the realization of diamond integrated quantum nanophotonic circuits on a chip.
Bray, K, Cheung, L, Hossain, KR, Aharonovich, I, Valenzuela, SM & Shimoni, O 2018, 'Versatile multicolor nanodiamond probes for intracellular imaging and targeted labeling', JOURNAL OF MATERIALS CHEMISTRY B, vol. 6, no. 19, pp. 3078-3084.View/Download from: Publisher's site
Tran, TT, Kianinia, M, Bray, K, Kim, S, Xu, Z-Q, Gentle, A, Sontheimer, B, Bradac, C & Aharonovich, I 2017, 'Nanodiamonds with photostable, sub-gigahertz linewidth quantum emitters', APL Photonics, vol. 2, no. 11, pp. 116103-116103.View/Download from: Publisher's site
Single-photon emitters with narrow linewidths are highly sought after for applications
in quantum information processing and quantum communications. In this
letter, we report on a bright, highly polarized near infrared single photon emitter
embedded in diamond nanocrystals with a narrow, sub-GHz optical linewidth
at 10 K. The observed zero-phonon line at ∼780 nm is optically stable under low
power excitation and blue shifts as the excitation power increases. Our results highlight
the prospect for using new near infrared color centers in nanodiamonds for
Tran, TT, Zachreson, C, Berhane, AM, Bray, K, Sandstrom, RG, Li, LH, 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: Publisher's site
Tran, TT, Bray, K, Ford, MJ, Toth, M & Aharonovich, I 2016, 'Quantum emission from hexagonal boron nitride monolayers.', Nature nanotechnology, vol. 11, no. 1, pp. 37-41.View/Download from: 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.
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: Publisher's site
Bray, K, Previdi, R, Gibson, BC, 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: Publisher's site