对称双阱中玻色-爱因斯坦凝聚体的量子隧穿的临界态

Critical State of Quantum Tunneling of Bose-Einstein Condensate in Symmetric Double Well

在半经典理论框架下利用平均场和双模近似理论研究在弱相互作用、无衰减效应和无周期调制时,在对称双阱中在两个玻色-爱因斯坦凝聚体(BEC)之间初始相位差分别为0和π的情况下临界态时BEC的动力行为,并进行了相应分析。由于系统是保守系统,在临界态时原子不会象有衰减效应时一样自动停止振荡,而是会作永不停止的无规则振荡。原子振荡在Josephson振荡和自捕获振荡之间的临界态时既呈现Josephson振荡的特征,又呈现自捕获振荡的特征,而在π相位模式自捕获振荡和φ(0)=π的runningphase模式自捕获振荡之间的临界态时既呈现π相位模式自捕获振荡的特征,又呈现φ(0)=π的runningphase模式自捕获振荡的特征。

In the framework of semi-classical theory, the author plots and analyzes the dynamical behaviors of Bose-Einstein condensate when initial phase difference is 0 and π, respectively, in a symmetric trap in weak interaction, without damping effects and periodical modulation. For the system is conservative, atoms never stop random oscillations in critical states instead of stopping automatically oscillations with damping effects. Atomic oscillations display properties of both Josephson oscillation and self-trapping oscillation in critical states between these two kinds of oscillation, and two kinds of properties of self-trapping oscillation in critical states between π phase mode self-trapping oscillation and running phase mode self-trapping oscillation.