Quantum thermodynamics for general bipartite interacting autonomous systems

TL;DR

This paper develops a consistent framework for defining internal energy and analyzing thermodynamics in interacting bipartite quantum systems using the Schmidt basis, ensuring minimal dissipation and uniqueness of the master equation.

Contribution

It introduces a novel approach to defining subsystem internal energies and thermodynamics in interacting quantum systems via the Schmidt basis formalism.

Findings

Master equation adheres to minimal dissipation

Subsystem internal energies are consistently defined

Provides insights into heat and work in quantum systems

Abstract

The internal energy of individual subsystems is not well defined in interacting quantum systems, leading to ambiguities in the definition of thermodynamic quantities. Applying the Schmidt basis formalism to general bipartite autonomous quantum systems, we demonstrate that the master equation describing subsystem evolution adheres to the principle of minimal dissipation. This enables to define internal energy of each subsystem in a consistent way. Moreover, by utilizing general aspects of open quantum systems, we show that this master equation is unique. We analyze heat and work for each subsystem as derived from this formalism, providing deeper insights into the thermodynamics of interacting quantum systems.