Phase‐Dependent Quantum Correlation in a Cavity‐Atom System

Abstract

A scheme to manipulate quantum correlation between output lights of a cavity-atom system by phase control is proposed. A driving-field phase is introduced which has a similar value with that of building up quantum correlation in a Hanbury-Brown-Twiss setup. A closed-loop phase is formed to improve quantum coherence by phase-dependent electromagnetically induced transparency. The closed-loop phase has been utilized to realize quantum correlation and even quantum entanglement in the atomic system of previous work. With these two phases, a steady and maximum quantum correlation has been obtained in the scheme here. Moreover, the maximum quantum correlation is free to decoherence of this cavity-atom system. The study on field-intensity correlation (quantum correlation) has potential applications on correlated imaging, image encryption transmission, and the improvement of noise resistance in a quantum network.

Controllable Nonclassical Correlation by an Incoherent Pumping Field in a Λ‐Type Atom‐Cavity System

“…[17,25] Consequently, it is crucial to manipulate and obtain stable quantum correlation for the development of quantum technology. [26] In one of our previous studies, [27] it is shown that the secondorder intensity correlation is also modified by the relative phase of the input probe fields, and the maximum stable correlation is attained when the relative phase is equal to 𝜋. In this paper, it is revealed that the maximum stable correlation is also generated in spite of zero relative phase, and the controllable secondorder intensity correlation is realized by a coherent coupling laser and an incoherent pumping field in a three-level atom-cavity system.…”