Speaker
Description
Solid-state sources of quantum light based on epitaxial quantum dots are rapidly approaching ideal performance: on-demand supply of single photons or entangled photon pairs in a pure quantum state delivered with unity efficiency into a specified quantum channel at GHz rates. Such dots are typically grown using the conventional strain-mediated Stranski–Krastanow growth or, more recently, using strain-free droplet epitaxy. Here we discuss a third growth technique based on vapour-liquid-solid epitaxy where the quantum dots are thin segments of a lower bandgap semiconductor incorporated within a larger bandgap nanowire. The bottom-up nanowire approach allows for precise control of the dot geometry, the number of dots within a nanowire, and their separation and is readily implemented with patterned-substrate epitaxy for position control. This contribution will outline the growth technique and illustrate the high quality of the sources in terms single photon collection efficiencies and multiphoton emission probabilities as well as the coherence properties of the generated photons. Approaches for coupling nanowire quantum dots with Si-based photonic integrated circuitry for on-chip operation or Si-based microcavities for high-rate operation will also be discussed.
