Dynamics of a multipartite system undergoing matter-state-photon conversions

Abstract

We examine the entanglement dynamics of two initially entangled qubits coupled to independent photon reservoirs and undergoing continuous matter-state–photon population transitions. We represent the decay and replenishment of matter-based bit states via photons by time-dependent generalized conversion functions. For the specific case of a sinusoidal function, we show that sudden death events in qubit–qubit entanglement anti-correlate (correlate) exactly with sudden birth events in photon–photon entanglement for the symmetric (anti-symmetric) mode of quantum conversions. We show the invariance in dynamics of all possible bipartite concurrences for various configurations of qubit–reservoir systems and highlight its crucial role in identifying a global concurrence of the multipartite system. We study the coherently driven quantum dot-cavity system as a specific application of our approach, including an analysis of evolution of its Meyer–Wallach measure with time.