Authors: Alireza Shabani, Jan Roden and Birgitta Whaley  (UC Berkeley)

Recent experimental advances in strong coupling of both individual and ensembles of quantum systems to a quantum oscillator have made cavity quantum electrodynamics an attractive platform to realize continuous measurement and real-time feedback control. In this work, we develop a formalism for continuous measurement of a complex quantum system with interacting components confined in a cavity. The formalism admits a non-perturbative and non-Markovian decoherence dynamics of the complex with the dynamics described by a hierarchy of stochastic equations of motion. We show that the effective continuously measured observable can be tuned just by tuning the cavity frequency.

Such a feature turns a cavity into a tool for continuous quantum state tomography: Wavefunction Video Camera.  Furthermore, we find that the non-Markovian nature of the decoherence dynamics can be revealed by studying the correlation properties of the detector current."