Quantum correlations of two qubits beyond entanglement in two lossy cavities linked by a waveguide

Abstract

We explore the quantum correlations (QCs) of two non-interacting two-level systems (qubits). Each qubit is embedded in an open cavity, the cavities are linked by an optical fiber and leak photons to the external environment. The quantum correlations are investigated via three different quantifiers (measurement-induced nonlocality, geometric quantum discord and negativity) under the effects of the coupling of the qubit-cavity and the fiber-cavity interactions as well as the cavity dissipations. It is found that the generation of QCs and their sudden birth and death phenomena, depend not only on the qubit-cavity and fiber-cavity couplings, but also on the initial states. The robustness of the QCs against the cavity dissipations can be enhanced in the regime of the ultra-strong cavity-fiber coupling. We convey that it is possible to control the quantum correlations, as well as to reduce the effect of cavity dissipation. © 2020 Elsevier Ltd

Keywords Cavity damping, Non-local correlations, Optical fiber