Unraveling Quantum Brownian Motion: Pointer States and their Classical Trajectories

TL;DR

This paper investigates the pointer states in quantum Brownian motion, deriving stochastic phase space trajectories that illustrate the quantum-to-classical transition through a Poissonian unraveling approach.

Contribution

It introduces a novel method to characterize pointer states and their trajectories, linking quantum dynamics to classical diffusion in phase space.

Findings

Pointer states are identified as soliton-like solutions of the master equation.

The phase space trajectories of pointer states resemble classical diffusion in the semiclassical limit.

The approach provides a clear picture of the quantum-classical transition in Brownian motion.

Abstract

We characterize the pointer states generated by the master equation of quantum Brownian motion and derive stochastic equations for the dynamics of their trajectories in phase space. Our method is based on a Poissonian unraveling of the master equation whose deterministic part exhibits soliton-like solutions that can be identified with the pointer states. In the semiclassical limit, their phase space trajectories turn into those of classical diffusion, yielding a clear picture of the induced quantum- classical transition.