Important building block for quantum technologies identified
Photons, known as “flying qubits”, are the information carriers of choice for future quantum technologies. To be of practical use, the devices that produce them, Single Photon Emitters (SPE), need to be able to operate both at room temperature and at “telecom wavelength”, at the same time. Up until now this has proved challenging.
Now, using a semi-conductor material made from Gallium Nitride (GaN), collaborators at Nanyang Technological University (NTU), Singapore, and The University of Technology Sydney (UTS) report, for the first time, the fabrication of an SPE that operates within both these criteria.
Professor Igor Aharonovich, deputy-director of the Institute for Biomedical Materials and Devices (IBMD), and an author on the paper published in Science Advances, says the identification of quantum emitters in a “technologically viable material” is an important step.
“This discovery will bring quantum technologies to reality much faster,” he says.
Operation of SPEs at room temperature is a practical consideration for quantum devices and using telecom wavelength is the most efficient way to transfer information via optical fibres.
Lead researcher Professor Wei-bo Gao, Leader of the Quantum Photonics group at NTU, says that “identifying sources at the telcom band means bringing quantum communications towards scalable commercial products.”
GaN is a commercially available blue-light semiconductor that is often can be found in DVDs. The research team pumped etched GaN wafers with laser light to produce the single photon emissions.
UTS physicist, Dr Sejeong Kim, an author on the paper says that semiconductor technology is “mature” which is an advantage because the material is relatively easy to fabricate and large wafers are available “off-the-shelf”.
“High performance SPEs embedded in a technologically mature semiconductor are promising for on-chip quantum simulators and practical quantum communication technologies,” she says.
Room-temperature solid state quantum emitters in the telecom range
Yu Zhou, Ziyu Wang, Abdullah Rasmita, Sejeong Kim, Amanuel Berhane, Zoltran Bodrog, Giorgio Adamo, Adam Gali, Igor Aharonovich, Wei-bo Gao
Science Advances (2018) doi10.1126/sciadv.aar3580