Zhang Chuanwei, Dudarev Artem M, Niu Qian
Department of Physics, The University of Texas, Austin, Texas 78712-1081, USA.
Phys Rev Lett. 2006 Jul 28;97(4):040401. doi: 10.1103/PhysRevLett.97.040401.
We study quasiparticle dynamics in a Bose-Einstein condensate with a vortex by following the center of mass motion of a Bogoliubov wave packet, and find important Berry-phase effects due to the background flow. We show that the Berry phase invalidates the usual canonical relation between the mechanical momentum and position variables, leading to important modifications of quasiparticle statistics and thermodynamic properties of the condensates. Applying these results to a vortex in an infinite uniform superfluid, we find that the total transverse force acting on the vortex is proportional to the superfluid density. We propose an experimental setup to directly observe Berry phase effects through measuring local thermal atoms' momentum distribution around a vortex.
我们通过跟踪玻戈留波夫波包的质心运动来研究具有涡旋的玻色 - 爱因斯坦凝聚体中的准粒子动力学，并发现了由于背景流引起的重要贝里相位效应。我们表明，贝里相位使机械动量和位置变量之间通常的正则关系无效，从而导致准粒子统计和凝聚体热力学性质的重要修正。将这些结果应用于无限均匀超流体中的涡旋，我们发现作用在涡旋上的总横向力与超流体密度成正比。我们提出了一种实验装置，通过测量涡旋周围局部热原子的动量分布来直接观测贝里相位效应。
