Fluctuation Theorems for a Quantum Channel

TL;DR

This paper develops a comprehensive quantum fluctuation theorem framework using the Petz recovery map, extending classical thermodynamic concepts to quantum channels and revealing new insights into quantum resource dynamics and irreversibility.

Contribution

It introduces a general quantum fluctuation theorem framework employing the Petz recovery map, incorporating complex entropy production and analyzing quantum resource fluctuations.

Findings

Established symmetry between forward and backward quantum channels.

Introduced complex-valued entropy production with physical interpretation.

Linked imaginary entropy part to quantum irreversibility and second law.

Abstract

We establish the general framework of quantum fluctuation theorems by finding the symmetry between the forward and backward transitions of any given quantum channel. The Petz recovery map is adopted as the reverse quantum channel, and the notion of entropy production in thermodynamics is extended to the quantum regime. Our result shows that the fluctuation theorems, which are normally considered for thermodynamic processes, can be a powerful tool to study the detailed statistics of quantum systems as well as the effect of coherence transfer in an arbitrary non-equilibrium quantum process. We introduce a complex-valued entropy production to fully understand the relation between the forward and backward processes through the quantum channel. We find the physical meaning of the imaginary part of entropy production to witness the broken symmetry of the quantum channel. We also show that the imaginary part plays a crucial role in deriving the second law from the quantum fluctuation theorem. The dissipation and fluctuation of various quantum resources including quantum free energy, asymmetry and entanglement can be coherently understood in our unified framework. Our fluctuation theorem can be applied to a wide range of physical systems and dynamics to query the reversibility of a quantum state for the given quantum processing channel involving coherence and entanglement.