Decoherence and the puzzle of quantum Brownian motion in a gas

TL;DR

This paper discusses the challenges of modeling quantum Brownian motion in gases, highlighting the need for modified dynamics due to decoherence, and critically examines existing quantum kinetic equations.

Contribution

It provides a critical analysis and open discussion of the quantum linear Boltzmann and quantum Fokker-Planck equations in the context of quantum Brownian motion.

Findings

Highlights the limitations of current quantum kinetic models

Emphasizes the importance of decoherence in quantum Brownian motion

Calls for further foundational research in quantum open systems

Abstract

Heinz-Dieter Zeh's discovery that the motion of macroscopic objects can not, under typical conditions, follow the Schr\"odinger equation necessitates a suitably modified dynamics. This unfolded a long-lasting puzzle in the open quantum system context: what is the quantum counterpart of the classical Brownian motion in a gas. Presented is a criticism and an open-end discussion of the quantum linear Boltzmann and quantum Fokker-Planck equations -- with constant respect for foundational research.