Critical Effects in Population Dynamics of Trapped Bose-Einstein Condensates
نویسندگان
چکیده
The population dynamics of a trapped Bose-Einstein condensate, subject to the action of an external field, is studied. This field produces a spatio-temporal modulation of the trapping potential with the frequency close to the transition frequency between the ground state and a higher energy level. For the evolution equations of fractional populations, a critical line is found. It is demonstrated that there exists a direct analogy between dynamical instability at this line and critical phenomena at a critical line of an averaged system. The related critical indices are calculated. The spatio-temporal evolution of atomic density is analyzed.
منابع مشابه
Analytical Estimate of the Critical Velocity for Vortex Pair Creation in Trapped Bose Condensates
We use a modified Thomas-Fermi approximation to analytically estimate the critical velocity for the formation of vortices in harmonically trapped BEC. We compare this analytical estimate to numerical calculations and to recent experiments on trapped alkali condensates. I. Introduction : The experimental realization of Bose-Einstein condensation (BEC) in cold trapped alkali atoms has stimulated ...
متن کاملCounting Statistics of a Bose-Einstein Condensate in a Double-Well Potential
This thesis aims to investigate the dynamic properties of ultra-cold Bose-Einstein condensates (BEC) trapped in a deep double well potential. Despite its simplicity, this system shows a rich variety of dynamical behaviors: Josephson oscillations, self-trapping behavior and critical dynamics. In contrast to previous studies, we aim to understand not only the first moment of the evolving occupati...
متن کاملTemperature Dependence of Vortex Nucleation in Gaseous Bose-Einstein Condensates
The formation of quantized vortices in trapped, gaseous Bose-Einstein condensates is considered. The thermodynamic stability of vortex states and the essential role of the surface excitations as a route for vortex penetration into the condensate are discussed. Special focus is on finite-temperature effects of the vortex nucleation process. It is concluded that the critical angular frequencies f...
متن کاملQuantized Vortex States and Dynamics in Bose-einstein Condensates
In this thesis, we analytically and numerically study quantized vortex states aswell as their dynamics in rotating Bose-Einstein condensate at extremely low tem-perature.We present an efficient method–gradient flow with discrete normalization tofind the stationary solutions of the Gross-Pitaevskii equation and coupled Gross-Pitaevskii equations. We give a mathematical justif...
متن کاملJosephson effects in dilute bose-einstein condensates
We propose an experiment that would demonstrate the dc and ac Josephson effects in two weakly linked Bose-Einstein condensates. We consider a time-dependent barrier, moving adiabatically across the trapping potential. The phase dynamics are governed by a "driven-pendulum" equation, as in current-driven superconducting Josephson junctions. At a critical velocity of the barrier (proportional to t...
متن کامل