Energy-tunable entangled photon sources on a III-V/Silicon chip

TL;DR

This paper presents a silicon-based hybrid photonic chip with energy-tunable, deterministic entangled photon sources using InAs/GaAs quantum dots, enabling scalable integration for advanced quantum photonic applications.

Contribution

It introduces a miniaturized, scalable hybrid chip with MEMS-based tuning of entangled photons from quantum dots on silicon, surpassing probabilistic sources.

Findings

Energy tunability exceeds 3000 times the radiative linewidth.

Deterministic quantum dot sources enable scalable integration.

Device footprint is several hundred microns.

Abstract

Many of the envisioned quantum photonic technologies, e.g. a quantum repeater, rely on an energy- (wavelength-) tunable source of polarization entangled photon pairs. The energy tunability is a fundamental requirement to perform two-photon-interference between different sources and to swap the entanglement. Parametric-down-conversion and four-wave-mixing sources of entangled photons have shown energy tunability, however the probabilistic nature of the sources limits their applications in complex quantum protocols. Here we report a silicon-based hybrid photonic chip where energy-tunable polarization entangled photons are generated by deterministic and scalable III-V quantum light sources. This device is based on a micro-electromechanical system (MEMS) incorporating InAs/GaAs quantum dots (QDs) on a PMNPT-on-silicon substrate. The entangled photon emissions from single QDs can be tuned by more than 3000 times of the radiative linewidth without spoiling the entanglement. With a footprint of several hundred microns, our design facilitates the miniaturization and scalable integration of indistinguishable entangled photon sources on silicon. When interfaced with silicon-based quantum photonic circuits, this device will offer a vast range of exciting possibilities.