On the speed of fluctuations around thermodynamic equilibrium

TL;DR

This paper investigates how quickly a quantum system fluctuates around its thermodynamic equilibrium, finding that such fluctuations are generally very slow for most times in typical thermodynamic scenarios.

Contribution

It provides a theoretical analysis of the fluctuation speed in quantum systems coupled to baths, extending previous work to more general equilibrium states.

Findings

Fluctuation speed is extremely small for almost all times in typical cases.

The study applies to a broad class of thermodynamic equilibrium states.

Results are consistent with the slow dynamics observed in quantum thermodynamics.

Abstract

We study the speed of fluctuation of a quantum system around its thermodynamic equilibrium state, and show that the speed will be extremely small for almost all times in typical thermodynamic cases. The setting considered here is that of a quantum system couples to a bath, both jointly described as a closed system. This setting, is the same as the one considered in [N. Linden et al., Phys. Rev. E 79:061103 (2009)] and the ``thermodynamic equilibrium state'' refers to a situation that includes the usual thermodynamic equilibrium case, as well as far more general situations.