Experimental Observation of Quantum Chaos in a Beam of Light

TL;DR

This paper demonstrates the experimental observation of quantum chaos by directly measuring the Wigner function of a quantum-kicked harmonic oscillator in light, revealing the transition from regular to chaotic quantum dynamics.

Contribution

It introduces a decoherence-free optical setup to observe quantum nonlinear dynamics and explores the transition from regular to chaotic behavior in a controllable manner.

Findings

Direct measurement of quantum chaos signatures in light

Controlled transition from regular to chaotic quantum dynamics

Investigation of decoherence effects due to chaos

Abstract

The manner in which unpredictable chaotic dynamics manifests itself in quantum mechanics is a key question in the field of quantum chaos. Indeed, very distinct quantum features can appear due to underlying classical nonlinear dynamics. Here we observe signatures of quantum nonlinear dynamics through the direct measurement of the time-evolved Wigner function of the quantum-kicked harmonic oscillator, implemented in the spatial degrees of freedom of light. Our setup is decoherence-free and we can continuously tune the semiclassical and chaos parameters, so as to explore the transition from regular to essentially chaotic dynamics. Owing to its robustness and versatility, our scheme can be used to experimentally investigate a variety of nonlinear quantum phenomena. As an example, we couple this system to a quantum bit and experimentally investigate the decoherence produced by regular or chaotic dynamics.