Efficient generation of single and entangled photons on a silicon photonic integrated chip

TL;DR

This paper introduces a silicon photonic chip that efficiently produces on-demand, indistinguishable single photons and entangled states, optimizing multiplexing and minimizing losses for scalable quantum photonics.

Contribution

It presents a novel protocol for high-efficiency, on-demand photon generation on a silicon chip using time-multiplexed SPDC with optimized loss and active element scaling.

Findings

Simulated improved single-photon-generation efficiency over previous protocols

Demonstrated potential for generating heralded Bell states

Identified fabrication improvements to enhance efficiency

Abstract

We present a protocol for generating on-demand, indistinguishable single photons on a silicon photonic integrated chip. The source is a time-multiplexed spontaneous parametric down-conversion element that allows optimization of single-photon versus multiphoton emission while realizing high output rate and indistinguishability. We minimize both the scaling of active elements and the scaling of active element loss with multiplexing. We then discuss detection strategies and data processing to further optimize the procedure. We simulate an improvement in single-photon-generation efficiency over previous time-multiplexing protocols, assuming existing fabrication capabilities. We then apply this system to generate heralded Bell states. The generation efficiency of both nonclassical states could be increased substantially with improved fabrication procedures.