Geometric quantum thermodynamics: A fibre bundle approach

TL;DR

This paper develops a geometric framework for quantum thermodynamics using fibre bundles, linking thermodynamic gauge theories with fundamental physics structures.

Contribution

It explicitly constructs principal fibre bundles for quantum thermodynamics and reveals two related geometric structures associated with gauge theories.

Findings

Identifies two distinct geometric structures in quantum thermodynamics.

Expresses thermodynamics using the language of principal fibre bundles.

Discusses how geometric properties may explain fundamental thermodynamic principles.

Abstract

Classical thermodynamics is a theory based on coarse-graining, meaning that the thermodynamic variables arise from discarding information related to the microscopic features of the system at hand. In quantum mechanics, however, where one has a high degree of control over microscopic systems, information theory plays an important role in describing the thermal properties of quantum systems. Recently, a new approach has been proposed in the form of a quantum thermodynamic gauge theory, where the notion of redundant information arises from a group of physically motivated gauge transformations called the thermodynamic group. In this work, we explore the geometrical structure of quantum thermodynamics. Particularly, we do so by explicitly constructing the relevant principal fibre bundle. We then show that there are two distinct (albeit related) geometric structures associated with the gauge theory of quantum thermodynamics. In this way, we express thermodynamics in the same mathematical (geometric) language as the fundamental theories of physics. Finally, we discuss how the geometric and topological properties of these structures may help explain fundamental properties of thermodynamics.