Electro-optic routing of photons from single quantum dots in photonic integrated circuits

TL;DR

This paper presents an integrated electro-optic phase shifter in gallium arsenide that actively routes photons from single quantum dots within photonic circuits, advancing chip-scale quantum photonics.

Contribution

It introduces a voltage-controlled phase shifter enabling active routing of single photons from quantum dots on a chip, a key step for scalable quantum photonic technologies.

Findings

Demonstrated a Mach-Zehnder interferometer with active photon routing

Achieved sub-microsecond electro-optic response time

Enabled integration of quantum emitters with active photonic control

Abstract

Recent breakthroughs in solid-state photonic quantum technologies enable generating and detecting single photons with near-unity efficiency as required for a range of photonic quantum technologies. The lack of methods to simultaneously generate and control photons within the same chip, however, has formed a main obstacle to achieving efficient multi-qubit gates and to harness the advantages of chip-scale quantum photonics. Here we propose and demonstrate an integrated voltage-controlled phase shifter based on the electro-optic effect in suspended photonic waveguides with embedded quantum emitters. The phase control allows building a compact Mach-Zehnder interferometer with two orthogonal arms, taking advantage of the anisotropic electro-optic response in gallium arsenide. Photons emitted by single self-assembled quantum dots can be actively routed into the two outputs of the interferometer. These results, together with the observed sub-microsecond response time, constitute a significant step towards chip-scale single-photon-source de-multiplexing, fiber-loop boson sampling, and linear optical quantum computing.