RAISE-TAQS: Integrated Room Temperature Single-Photon based Quantum-Secure LiFi Systems

Cornell University, Ithaca NY

Investigators

Abstract

Gallium Nitride based LEDs have revolutionized solid-state lighting. Because unlike incandescent bulbs, LEDs can be switched and modulated at GHz frequencies, they are enabling light fidelity (LiFi) as a means of point to point communications using visible light in free space. LiFi is similar to WiFi, but its penetration is expected to rival, or exceed WiFi as GaN LEDs replace residential, industrial, street, and automotive lighting. Making free- space LiFi communication secure in the quantum sense in the future is both a timely opportunity, and of paramount technological importance. Secure communication systems are possible using the quantum properties of single-photons that prevent eavesdropping, and guarantee security. A successful demonstration of the devices and systems proposed in this research would not just enhance security in the rapidly emerging LiFi networks but also make quantum technologies come out from the research labs and reach people's houses. The proposed research is therefore highly transformative. In addition, the strong emphasis on material and device physics, optical and quantum sciences, and communication networks will all provide a rich set of areas for exploration and graduate student research. Technical: The PIs of this proposal have discovered single photon sources in wide-bandgap nitrides that are 20x brighter than the NV centers in diamond, and importantly, operate at room temperature. They have developed a fundamentally new structure for nitride LEDs using buried tunnel junctions, with which it becomes possible to electrically pump the single photon emitter. The engineering-led goals of the proposed project are threefold: (a) To build the first room-temperature electrically pumped on-demand single photon source completely integrated on the GaN material system, (b) To design and characterize the spectral properties, bandwidth, efficiency, packing density, and potential entanglement properties of the nitride single photon sources, and (c) To theoretically and experimentally identify and test the fundamental requirements, and limits of quantum-secure LiFi communication systems. This project explores and exploits the physics of single photon emitters, advances in quantum materials, and secure LiFi systems design and engineering, leading to the implementation quantum Lifi in a practical way. Every step in this quest will accelerate the development and deployment of quantum technologies. The team will systematically explore the basic physics of h-BN quantum emitters and III-nitride quantum dots, their emission rates and wavelengths, and how we can create these emitters deterministically. The Pis seek to discover how to integrate bright III-nitride LED structures with quantum emitters and efficiently gather the quantum and classical light in separate channels. Finally, they will engineer these devices in a real-world context and deploy them to ensure private communications guaranteed by the laws of quantum physics. New nitride quantum crystalline materials are key to this proposal. A meaningful international collaboration is proposed with a leading nitride materials group in the world will offer some of the highest quality gallium nitride crystals in the world. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.