Thermodynamics of information exchange between two coupled quantum dots

TL;DR

This paper presents a quantum dot setup that models thermodynamics of measurement and feedback, demonstrating how information can seemingly violate the second law, and derives fluctuation relations for entropy production.

Contribution

It introduces a quantum dot system that acts as a Maxwell's Demon, analyzing thermodynamics at the single-realization level and deriving fluctuation relations for entropy.

Findings

The setup can operate as a Maxwell's Demon with separate measurement and feedback.

Integral fluctuation relations are derived for entropy production.

The operation is explained at the level of single realizations.

Abstract

We propose a setup based on two coupled quantum dots where thermodynamics of a measurement can be quantitatively characterized. The information obtained in the measurement can be utilized by performing feedback in a manner apparently breaking the second law of thermodynamics. In this way the setup can be operated as a Maxwell's Demon where both the measurement and feedback are performed separately by controlling an external parameter. This is analogous to the case of the original Szilard engine. Since the setup contains both the microscopic demon and the engine itself, the operation of the whole measurement-feedback cycle can be explained in detail at the level of single realizations. In addition, we derive integral fluctuation relations for both the bare and coarse-grained entropy productions in the setup.