Tripartite quantum state mapping and discontinuous entanglement transfer in a cavity QED open system

TL;DR

This paper investigates how quantum information and entanglement transfer between flying radiation qubits and localized atomic qubits in a cavity QED system, considering dissipative effects and entanglement dynamics.

Contribution

It provides a detailed analysis of multipartite entanglement transfer and oscillations, including the phenomenon of discontinuous entanglement exchange in an open system.

Findings

Optimal fidelity and entanglement transfer when cavities are fed

Exponential decrease of peak entanglement due to dissipation

Discontinuous entanglement exchange in multipartite states

Abstract

We describe the transfer of quantum information and entanglement from three flying (radiation) to three localized (atomic) qubits via cavity modes resonantly coupled to the atoms, in the presence of a common reservoir. Upon addressing the full dynamics of the resulting nine-qubit open system, we find that once the cavities are fed, fidelity and transferred entanglement are optimal, while their peak values exponentially decrease due to dissipative processes. The external radiation is then turned off and quantum correlations oscillate between atomic and cavity qubits. For a class of mixtures of W and GHZ input states we deal with a discontinuous exchange of entanglement among the subsystems, facing the still open problem of entanglement sudden death and birth in a multipartite system.