Work distribution in a photonic system

TL;DR

This paper proposes an optical setup to measure work distribution in a quantum harmonic oscillator system using light modes, enabling experimental access to quantum thermodynamics concepts.

Contribution

It introduces a novel optical interferometric method to directly measure work distribution for arbitrary unitaries acting on photonic modes.

Findings

The Fourier transform of the work distribution can be obtained from output intensities.

The method is feasible with simple linear optical components.

Application demonstrated for a displacement operation in momentum space.

Abstract

We present a proposal of a set-up to measure the work distribution due to an arbitrary unitary process acting on the spatial transverse degrees of freedom of a light beam. Hermite-Gaussian optical modes representing a quantum harmonic oscillator are prepared in a thermal state and sent through an interferometer. We show that the Fourier transform of the work distribution, or the characteristic function, can be obtained by measuring the intensity at the output of the interferometer. The usefulness of the approach is illustrated by calculating the work distribution for a unitary operation that displaces the linear momentum of the oscillator. We discuss the feasibility of the experiment, which can be realized with simple linear optical components.