Available on-demand - *S.EL06.09.02
Quantum Photonics with InAs Quantum Dots
National Institute of Standards and Technology1
Photonic quantum technologies rely on the fact that photons can be endowed with long coherence times, can travel long distances at light-speed, and interact only weakly with the environment, thereby constituting near-ideal carriers of quantum information. Single-photon qubits are a core resource for many quantum technologies currently being developed for systems that, based on quantum mechanical effects, have great potential to perform communication, signal processing, computation and measurements with significantly superior security, efficiency and sensitivity [1–3]. In such applications, an ideal quantum light source would emit a pure, high-rate stream of highly indistinguishable single-photons produced on-demand. Single-photon sources based on single quantum emitters – such as quantum dots, organic molecules, point-defects in solids, etc. - have a great potential to fulfill all such requirements. Among the various types of single quantum emitters available in the solid-state, self-assembled InAs/GaAs quantum dots constitute the most promising material system to date , having been used to demonstrate triggered single-photon emission with indistinguishability close to that of spontaneous pair sources, and orders or magnitude higher generation rates [5, 6]. Such quantum dots consist of nanometer-scale islands of InAs that are grown epitaxially in a GaAs host, and are operated at cryogenic temperatures. Importantly, the ability to produce quantum dots within high index contrast GaAs nanophotonic geometries enables strong control of crucial quantum dot emission characteristics, such as the excited state decay rate and outcoupling into select spatial modes [5–7]. The former characteristic translates into control of the single-photon emission rate and, to some degree, coherence. The latter translates into efficient funneling of the single-photons into a useful, output optical spatial mode – e.g., a low-divergence Gaussian beam [7, 8] or a single optical fiber mode  -, which has a strong impact on the overall source efficiency. This talk will describe our progress in developing high efficiency single-photon sources based on self-assembled InAs/GaAs quantum dots in nanophotonic structures. In particular, because the availability of mature chip-scale photonic integration techniques provides compelling advantages towards scalable photonic quantum systems, our recent results on deterministic fabrication of heterogeneous integrated photonic devices with single quantum dot based sources of on-chip waveguide-coupled single-photons [10, 11] will be covered.
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