Coherence and Fluctuations in the Interaction between Moving Atoms and a Quantum Field

摘要

Mesoscopic physics deals with three fundamental issues: quantum coherence,fluctuations and correlations. Here we analyze these issues for atom optics,using a simplified model of an assembly of atoms (or detectors, which areparticles with some internal degree of freedom) moving in arbitrarytrajectories in a quantum field. Employing the influence functional formalism,we study the self-consistent effect of the field on the atoms, and their mutualinteractions via coupling to the field. We derive the coupled Langevinequations for the atom assemblage and analyze the relation of dissipativedynamics of the atoms with the correlation and fluctuations of the quantumfield. This provides a useful theoretical framework for analysing the coherentproperties of atom-field systems.