Programmable quantum circuits in a large-scale photonic waveguide array

TL;DR

This paper demonstrates precise control of single-photon states in a large-scale, programmable photonic waveguide array, showcasing its potential for scalable quantum information processing.

Contribution

First demonstration of controlling single-photon states in an 11x11 programmable waveguide array with high visibility and tunable interference.

Findings

Achieved maximum quantum interference visibility of 0.962

Controlled multiple subcircuits simultaneously on a single device

Showcased potential for scalable quantum information processing

Abstract

Over the past decade, integrated quantum photonic technologies have shown great potential as a platform for studying quantum phenomena and realizing large-scale quantum information processing. Recently, there have been proposals for utilizing waveguide lattices to implement quantum gates, providing a more compact and robust solution compared to discrete implementation with directional couplers and phase shifters. We report on the first demonstration of precise control of single photon states on an $11\times 11$ continuously-coupled programmable waveguide array. Through electro-optical control, the array is subdivided into decoupled subcircuits and the degree of on-chip quantum interference can be tuned with a maximum visibility of 0.962$\pm$0.013. Furthermore, we show simultaneous control of two subcircuits on a single device. Our results demonstrate the potential of using this technology as a building block for quantum information processing applications.