Quantum H-theorem and irreversibility in quantum mechanics

TL;DR

This paper explores how von Neumann entropy increases in quantum systems, linking irreversibility to decoherence, entanglement, and wave function partitioning, thus providing insights into quantum thermodynamics.

Contribution

It introduces a quantum H-theorem demonstrating entropy growth and irreversibility arising from quantum state complexity and entanglement.

Findings

Von Neumann entropy increases with decoherence during scattering.

Irreversibility is rooted in entanglement and wave function partitioning.

Entropy growth correlates with system complexity and state preparation difficulty.

Abstract

We investigate temporal evolution of von Neumann's entropy in exemplary quantum mechanical systems and show that it grows in systems evolving with incrementally increasing decoherence during scattering processes. We demonstrate that the origin of irreversibility lies in complexity of preparing time-reversed quantum states due to entanglement and in partitioning of the wave function of the evolving system.