Improved bound on entropy production in a quantum annealer

TL;DR

This paper derives a tighter lower bound on entropy production in quantum annealers based on the asymmetry of probability distributions, improving estimation accuracy of dissipation in quantum thermodynamics.

Contribution

It introduces a new, tighter lower bound on entropy production that surpasses previous bounds and demonstrates its application to experimental quantum annealing data.

Findings

The new bound is mathematically tighter than previous bounds.

Application to quantum annealing yields the most accurate dissipation estimates to date.

The bound is shown to be saturable in certain cases.

Abstract

For a system described by a multivariate probability density function obeying the fluctuation theorem, the average dissipation is lower-bounded by the degree of asymmetry of the marginal distributions (namely the relative entropy between the marginal and its mirror image). We formally prove that such lower bound is tighter than the recently reported bound expressed in terms of the precision of the marginal (i.e., the thermodynamic uncertainty relation) and is saturable. We illustrate the result with examples and we apply it to achieve the most accurate experimental estimation of dissipation associated to quantum annealing to date.