Efficient Generation of N-Photon Bundles Using a Solid State Cavity QED System

Stanford University, Stanford CA

Investigators

Abstract

Non-technical description The goal of this project is to develop a new platform (system) for studying the strong interaction between light and matter, and to employ it to generate pulses of light containing a precisely determined integer number (n) of indivisible particles of light - photons. The system comprises a set of nano-sized mirrors that recirculate light (a nanoscale cavity) around a semiconductor artificial atom (a quantum dot). This enables a strong interaction between individual photons, which is otherwise impossible. The system is probed with a series of laser pulses (consisting of non-interacting photons, where the number of photons per pulse is not well-defined). When laser pulses enter this medium, the medium filters (selects) a desired number of photons per each pulse and transmits them to the output. The potential applications include improvements in secure quantum communication, quantum simulation, and quantum sensing. This work therefore combines photonic and quantum engineering with materials science, nanotechnology, and fundamental physics. The project contains educational and outreach activities integrated with research, including active recruitment of minorities and women for science and engineering careers, development of new classes and textbooks, undergraduate research and advising, and participation in outreach programs for K-12 students and teachers. Technical description The focus of this project is to continue fundamental studies of quantum dot-nanocavity quantum electrodynamics, and more specifically, to explore the strong nonlinear properties of such systems in the detuned regime, and to use the knowledge gained from these studies to develop on-chip sources of highly correlated photons (indistinguishable single photons and n-photon bundles on demand). A platform to achieve these goals consists of high quality factor and small mode volume photonic crystal resonators that are coupled to single, electrically tunable quantum dots. This approach can lead to nearly perfect photon indistinguishability and high photon bundle generation rates, while preferentially generating the desired number of photons per pulse. The specific research goals are to study the resonantly driven and detuned strongly coupled quantum dot-cavity system, and to use it to develop sources of indistinguishable single photons and n-photon bundles on demand with high count rates. The ability to generate nonclassical states of light beyond the single-photon level paves the way for novel concepts in quantum communication and quantum sensing. Therefore, the research activities described here have a broad impact on not only the communities focused on quantum nanophotonics or nonlinear optics, but also on those exploring sensors or quantum technologies.