Coherence in Cooperative Photon Emission from Indistinguishable Quantum Emitters

TL;DR

This paper investigates how coherence influences cooperative photon emission from two distant, indistinguishable solid-state emitters, demonstrating control over their quantum correlations and advancing quantum photonic network development.

Contribution

It introduces experimental techniques to control and characterize coherence-driven cooperative emission between matter qubits using quantum optics methods.

Findings

Photon bunching indicates cooperative emission and emitter indistinguishability.

Photon statistics from indistinguishable emitters resemble a weak coherent state.

Techniques established for controlling quantum correlations in matter qubits.

Abstract

Photon-mediated interactions between atomic systems can arise via coupling to a common electromagnetic mode or by quantum interference. Here, we probe the role of coherence in cooperative emission arising from two distant but indistinguishable solid-state emitters because of path erasure. The primary signature of cooperative emission, the emergence of "bunching" at zero delay in an intensity correlation experiment, is used to characterise the indistinguishability of the emitters, their dephasing, and the degree of correlation in the joint system that can be coherently controlled. In a stark departure from a pair of uncorrelated emitters, in Hong-Ou-Mandel type interference measurements we observe photon statistics from a pair of indistinguishable emitters resembling that of a weak coherent state from an attenuated laser. Our experiments establish techniques to control and characterize cooperative behavior between matter qubits using the full quantum optics toolbox, a key step toward realizing large-scale quantum photonic networks.