Complete positivity and thermodynamics in a driven open quantum system

TL;DR

This paper investigates how violations of complete positivity in open quantum systems can be experimentally detected through current measurements, shedding light on thermodynamics consistency in quantum dynamics.

Contribution

It proposes using current measurements in a quantum micro-circuit to distinguish between non-completely positive and completely positive dynamics, testing thermodynamics laws.

Findings

Current differences indicate non-complete positivity.

Experimental method to verify thermodynamics in quantum systems.

Discrimination between Redfield and standard weak-coupling dynamics.

Abstract

While it is well known that complete positivity guarantees the fulfilment of the second law of thermodynamics, its possible violations have never been proposed as a check of the complete positivity of a given open quantum dynamics. We hereby consider an open quantum micro-circuit, effectively describable as a two-level open quantum system, whose asymptotic current might be experimentally accessible. This latter could indeed be used to discriminate between its possible non-completely positive Redfield dynamics and a completely positive one obtained by standard weak-coupling limit techniques, at the same time verifying the fate of the second law of thermodynamics in such a context.