Quantum feedback in cavity quantum electrodynamics

B.C. Roy, Pradip Das

The present article is concerned with the study of quantum electrodynamics (QED) in interacting Fock space and a generalised approach of modelling quantum feedback systems of the optical QED cavities. The dynamical behaviour and the state space representation in stochastic field of the optical QED system provide the basis for developing quantum feedback QED control system. This study is also motivated by the design of quantum networks of any number of optical QED baths connected in parallel. Nyquist stability of the feedback control system in the interacting Fock space using two-mode beam splitter device at the input and a single-mode fractional beam splitter device at the output of the cavity has been analysed. The degree of stability of the quantum feedback control system of the cavity QED is studied by measuring gain margin and phase margin of the system in terms of parameters of the beam splitter.

S. Haroche, Daniel Kleppner

Pradip Das, B. C. Roy

In this paper we introduce a formulation of the quantum mechanical feedback system in order to understand the quantum system in interacting Fock space which generalizes the transfer function approach to the quantum mechanical feedback system studied in bosonic mode. A mathematical model of the feedback control of the cavity quantum electrodynamic system in the interacting Fock space with the second cavity in the feedback path is described using a beam splitter.

Abubakr Muhammad, Motivational Examples

Alexander Carmele, Julia Kabuß, Franz Schulze +2 more

We propose a scheme to control cavity quantum electrodynamics in the single photon limit by delayed feedback. In our approach a single emitter-cavity system, operating in the weak coupling limit, can be driven into the strong coupling-type regime by an external mirror: The external loop produces Rabi oscillations directly connected to the electron-photon coupling strength. As an expansion of typical cavity quantum electrodynamics, we treat the quantum correlation of external and internal light modes dynamically and demonstrate a possible way to implement a fully quantum mechanical time-delayed feedback. Our theoretical approach proposes a way to experimentally feedback control quantum correlations in the single photon limit.