Quantum noise of a Bose-Einstein condensate in an optical cavity, correlations and entanglement

TL;DR

This paper investigates the quantum noise, correlations, and entanglement in a Bose-Einstein condensate within an optical cavity, revealing the robustness of the condensate against entanglement across most of the phase diagram.

Contribution

It introduces a mean-field and linearized fluctuation analysis of the condensate-cavity system, providing new insights into entanglement and quantum statistics in this setup.

Findings

Bose-Einstein condensate exhibits dispersive optical bistability.

Entanglement is generally suppressed in the mean-field state.

Stationary state correlations and quadrature statistics are characterized.

Abstract

A Bose-Einstein condensate of ultracold atoms inside the field of a laser-driven optical cavity exhibits dispersive optical bistability. We describe this system by using mean-field approximation and by analyzing the correlation functions of the linearized quantum fluctuations around the mean-field solution. The entanglement and the statistics of the atom-field quadratures are given in the stationary state. It is shown that the mean-field solution, i.e. the Bose-Einstein condensate is robust against entanglement generation for most part of the phase diagram.