Discrete single-photon quantum walks with tunable decoherence

TL;DR

This paper demonstrates a stable, deterministic method for implementing discrete quantum walks with single photons, allowing tunable decoherence to study quantum-to-classical transition and absorption effects.

Contribution

It introduces a scalable, stable optical setup for quantum walks with tunable decoherence, enabling detailed exploration of quantum-to-classical transition effects.

Findings

Quantum walks with up to 6 steps demonstrated

Tunable decoherence affects the quantum-to-classical transition

Decoherence influences absorption probabilities in quantum walks

Abstract

Quantum walks have a host of applications, ranging from quantum computing to the simulation of biological systems. We present an intrinsically stable, deterministic implementation of discrete quantum walks with single photons in space. The number of optical elements required scales linearly with the number of steps. We measure walks with up to 6 steps and explore the quantum-to-classical transition by introducing tunable decoherence. Finally, we also investigate the effect of absorbing boundaries and show that decoherence significantly affects the probability of absorption.