Output entanglement and squeezing of two-mode fields generated by a single atom

TL;DR

This paper demonstrates how a single four-level atom can generate entangled and squeezed two-mode fields through cavity interactions, with controllable properties influenced by detuning and initial states.

Contribution

It introduces an effective Hamiltonian approach showing that a single atom can produce entangled and squeezed two-mode fields, highlighting the roles of detuning and cavity leakage.

Findings

Entanglement and squeezing are achievable in output fields.

Asymmetric detuning splits the squeezing spectrum into two minima.

Cavity leakage is necessary for output entanglement.

Abstract

A single four-level atom interacting with two-mode cavities is investigated. Under large detuning condition, we obtain the effective Hamiltonian which is unitary squeezing operator of two-mode fields. Employing the input-output theory, we find that the entanglement and squeezing of the output fields can be achieved. By analyzing the squeezing spectrum, we show that asymmetric detuning and asymmetric atomic initial state split the squeezing spectrum from one valley into two minimum values, and appropriate leakage of the cavity is needed for obtaining output entangled fields.