EAGER: Toward Monolithic Optically-Pumped Single-Photon Sources Based on Deterministic InGaN Quantum Dots in GaN Nanowires

Ohio State University, The, Columbus OH

Investigators

Abstract

Single-photon sources are one of most useful basic building blocks for many future quantum technologies. In particular, quantum communication, quantum computing and quantum sensing are the areas that can be revolutionized by the development of high-performance single-photon sources. In order to enable these practical quantum applications, such photon sources must be robust, coherent, tunable and bright, and they should exhibit high- light-collection efficiency and -directionality at the same time. To date, no technology options can provide such a quantum light source that simultaneously combines all of these key properties. This project aims to develop a single-photon source that can meet these aggressive performance specifications. Such unprecedented performance will enable future development of a photonic integrated circuit platform that will simultaneously improve performance and efficiency as well as help meet low size, weight and power-cost constraints for next-generation quantum photonic technologies. In addition to high impact research advancement, our project will also support interdisciplinary education activities in nanoscience and nanotechnology. Because the proposed research project crosses different disciplines of science and engineering, such as optics, materials science, electrical engineering, physics, and chemistry, it will lead to a range of potential, hands-on learning activities that can engage students of varying backgrounds. The primary research objective of the proposed project is to advance intellectual understanding of non-classical light sources through the development of novel photonic platforms that require growth of one-dimensional III-nitride nanowire (NW) structures. This advancement will enable practical quantum technologies at wavelengths ideally suited for long-distance quantum networks with existing fiber-optic telecommunication infrastructures. In this EAGER proposal, we explore a new and unique technique for the growth of nitrogen (N)-polar GaN NWs with InGaN quantum dots (QDs) deterministically placed inside using a bottom-up approach via plasma-assisted molecular beam epitaxy (PAMBE). Unlike a top-down technique, the bottom-up growth method allows proper placement of QDs on the axis of tapered NW-waveguides and an improved light extraction with reduced tapering angles on top of NWs. The long-term objective of the proposed research is to achieve bright and ultra-spectrally pure single-photon sources (SPSs) that meet aggressive performance specifications, such as high count rate and near-zero auto-correlation factors for high-fidelity entanglement. The work performed within this EAGER project will serve as a foundation for designing highly-efficient and coherent tunable SPSs. The project will advance knowledge on the MBE growth of the InGaN/GaN QDs within NWs and the associated growth conditions including polarity and growth rate control. The deterministic QD-NWs based SPSs and its emission properties will be well-understood from the study. This project will also generate technical advancements to push the light emission towards longer wavelengths for the NW-based device technologies by increasing the indium incorporation within QDs and controlling the polarity of NWs. The proposed research will lead to deeper fundamental insights into mechanisms and processes involved in scalable quantum photonic devices and integrated circuits. This inherently interdisciplinary research combines material science, quantum physics, chemical engineering and electrical engineering to generate new fundamental knowledge in several scientific fields, indicating that the concept is highly novel and transformative. 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.