Cavity-enhanced coherent light scattering from a quantum dot

TL;DR

This paper demonstrates that a microcavity enhances coherent photon scattering from a quantum dot, enabling high-quality indistinguishable photon generation and super-resolving phase measurements, advancing solid-state quantum photonics.

Contribution

It shows cavity-enhanced coherent scattering from a quantum dot, achieving near-unity resonant scattering and generating N00N states for quantum metrology.

Findings

Enhanced resonant scattering fraction approaching unity

Generation of anti-bunched indistinguishable photons beyond the time-bandwidth limit

Creation of 2-photon N00N states for super-resolving phase measurements

Abstract

Resonant excitation of atoms and ions in macroscopic cavities has lead to exceptional control over quanta of light. Translating these advantages into the solid state with emitters in microcavities promises revolutionary quantum technologies in information processing and metrology. Key is resonant optical reading and writing from the emitter-cavity system. However, it has been widely expected that the reflection of a resonant laser from a micro-fabricated wavelength-sized cavity would dominate any quantum signal. Here we demonstrate coherent photon scattering from a quantum dot in a micro-pillar. The cavity is shown to enhance the fraction of light which is resonantly scattered towards unity, generating anti-bunched indistinguishable photons a factor of 16 beyond the time-bandwidth limit, even when the transition is near saturation. Finally, deterministic excitation is used to create 2-photon N00N states with which we make super-resolving phase measurements in a photonic circuit.