Thermodynamics of discrete quantum processes

TL;DR

This paper develops a framework for understanding thermodynamics in discrete quantum processes, defining heat, work, and the second law for sequences of quantum configurations, including reversible and Carnot cycles.

Contribution

It introduces a novel approach to quantum thermodynamics by defining primitives of discrete processes and deriving fundamental thermodynamic laws for these sequences.

Findings

A general second law for discrete quantum trajectories

Recovery of Carnot efficiency in quantum cycles

Validation of thermodynamic principles in non-equilibrium quantum processes

Abstract

We define thermodynamic configurations and identify two primitives of discrete quantum processes between configurations for which heat and work can be defined in a natural way. This allows us to uncover a general second law for any discrete trajectory that consists of a sequence of these primitives, linking both equilibrium and non-equilibrium configurations. Moreover, in the limit of a discrete trajectory that passes through an infinite number of configurations, i.e. in the reversible limit, we recover the saturation of the second law. Finally, we show that for a discrete Carnot cycle operating between four configurations one recovers Carnot's thermal efficiency.