Decoherence and entanglement in tripartite systems: Cavity QED

TL;DR

This paper proposes a feasible cavity QED experiment to study how dissipation affects entanglement in a tripartite system, providing analytical and numerical results showing persistent entanglement under realistic conditions.

Contribution

It introduces an experimental setup with analytical expressions for system evolution and entanglement measures, advancing understanding of decoherence effects in cavity QED.

Findings

Cavity fields remain entangled despite dissipation.

Analytical expressions for evolution superoperator derived.

Numerical calculations confirm entanglement persistence.

Abstract

We propose an experimental setup, feasible with present day technology, involving two highquality- factor cavities, one Ramsey zone and a two-level atom which interacts with them. The dynamics in the cavities is modeled by a dissipative dispersive Jaynes-Cummings model. Analytical expresions for the evolution superoperator in each part of the proposed setup and for the concurrence between the atom and the first cavity are given, and the pairwise entanglement of the subsystems is calculated numerically. We consider initial separable states given by the tensor product of a superposition of the two atomic relevant states and coherent states for the fields. We show that for realistic model parameters (including dissipation), when the dissipation rates are smaller than the dispersive frequencies (the ratio between the squared vacuum Rabi frequencies and the detunings), the final state of the cavity fields remains entangled.