Creation of pure multi-mode entangled states in a ring cavity

TL;DR

This paper proposes a practical method to generate multi-mode entangled states of atomic ensembles in a ring cavity using laser-driven interactions and cavity dissipation, enabling controlled quantum state preparation.

Contribution

It introduces a novel scheme for creating multi-mode squeezed states in atomic ensembles within a ring cavity, utilizing laser fields and cavity dissipation for state engineering.

Findings

Successful construction of multi-mode squeezed states from vacuum.

Use of laser pulses and cavity dissipation to stabilize desired states.

Procedure applicable to ultra-cold atomic ensembles in ring cavities.

Abstract

Practical schemes for creation of multi-mode squeezed (entangled) states of atomic ensembles located inside a high-Q ring cavity are discussed. It is assumed that the cavity is composed of two degenerate mutually counter-propagating modes that can simultaneously couple to the atomic ensembles with the same coupling strengths. The ensembles are composed of ultra-cold atoms which are modeled as four-level systems driven by two laser fields, both co-propagating with one of the cavity directions. We illustrate a procedure that constructs multi-mode squeezed states from the vacuum by a unitary transformation associated with the collective dynamics of the atomic ensembles subjected to driving lasers of a suitably adjusted amplitudes and phases. The lasers pulses together with the cavity dissipation prepare the collective modes in a desired stationary squeezed state.