Eliminating temporal correlation in quantum-dot entangled photon source by quantum interference

Sci Bull (Beijing). 2023 Apr 30;68(8):807-812. doi: 10.1016/j.scib.2023.03.022. Epub 2023 Mar 16.

Abstract

Semiconductor quantum dots, as promising solid-state platform, have exhibited deterministic photon pair generation with high polarization entanglement fidelity for quantum information applications. However, due to temporal correlation from inherently cascaded emission, photon indistinguishability is limited, which restricts their potential scalability to multi-photon experiments. Here, by utilizing quantum interferences to decouple polarization entanglement from temporal correlation, we improve four-photon Greenberger-Horne-Zeilinger (GHZ) state entanglement fidelity from (58.7±2.2)% to (75.5±2.0)%. Our work paves the way to realize scalable and high-quality multi-photon states from quantum dots.

Keywords: Entangled photon source; Microcavity; Quantum information; Quantum interference; Single quantum dot.