Nonlinear Coherent Modes of Trapped Bose-Einstein Condensates

TL;DR

This paper develops a comprehensive theory for resonant excitation of nonlinear coherent modes in trapped Bose-Einstein condensates, revealing critical phenomena and potential for quantum interference and entanglement.

Contribution

It provides the first detailed theoretical framework for resonant excitation of nonlinear modes in BECs, including conditions for feasibility and analysis of dynamic critical phenomena.

Findings

Identification of conditions for resonant excitation of coherent modes

Observation of dynamic critical phenomena in fractional populations

Features like interference patterns and entanglement in atomic clouds

Abstract

Nonlinear coherent modes are the collective states of trapped Bose atoms, corresponding to different energy levels. These modes can be created starting from the ground state condensate that can be excited by means of a resonant alternating field. A thorough theory for the resonant excitation of the coherent modes is presented. The necessary and sufficient conditions for the feasibility of this process are found. Temporal behaviour of fractional populations and of relative phases exhibits dynamic critical phenomena on a critical line of the parametric manifold. The origin of these critical phenomena is elucidated by analyzing the structure of the phase space. An atomic cloud, containing the coherent modes, possesses several interesting features, such as interference patterns, interference current, spin squeezing, and massive entanglement. The developed theory suggests a generalization of resonant effects in optics to nonlinear systems of Bose-condensed atoms.