Friction as a consistent quantum-mechanical concept

TL;DR

This paper introduces a quantum master equation model that describes friction in quantum systems with internal states coupled to translational motion, challenging previous assumptions about quantum friction and detailed balance.

Contribution

It presents a novel quantum master equation for friction in systems with internal states, extending the understanding of dissipation in quantum mechanics.

Findings

Derived a quantum master equation for friction at zero temperature

Provided an analytical example illustrating the model

Formulated conjectures for finite temperature scenarios

Abstract

A quantum analog of friction (understood as a completely positive, Markovian, translation-invariant and phenomenological model of dissipation) is known to be in odds with the detailed balance in the thermodynamic limit. We show that this is not the case for quantum systems with internal (e.g. spin) states non-adiabatically coupled to translational dynamics. For such systems, a quantum master equation is derived which phenomenologically accounts for the frictional effect of a uniform zero temperature environment. A simple analytical example is provided. Conjectures regarding the finite temperature case are also formulated. The results are important for efficient simulations of complex molecular dynamics and quantum reservoir engineering applications.