Capturing vacuum fluctuations and photon correlations in cavity quantum electrodynamics with multitrajectory Ehrenfest dynamics

摘要

We describe vacuum fluctuations and photon-field correlations in interacting quantum mechanical light-matter systems by generalizing the application of mixed quantum classical dynamics techniques.We employ the multitrajectory implementation of Ehrenfest mean-field theory,traditionally developed for electron-nuclear problems,to simulate the spontaneous emission of radiation in a model quantum electrodynamical cavity-bound atomic system.We investigate the performance of this approach in capturing the dynamics of spontaneous emission from the perspective of both the atomic system and the cavity photon field through a detailed comparison with exact benchmark quantum mechanical observables and correlation functions.By properly accounting for the quantum statistics of the vacuum field,while using mixed quantum classical (mean-field) trajectories to describe the evolution,we identify a surprisingly accurate and promising route towards describing quantum effects in realistic correlated light-matter systems.