Giovanazzi S, Smerzi A, Fantoni S
Istituto Nazionale di Fisica della Materia and International School for Advanced Studies, via Beirut 2/4, I-34014, Trieste, Italy.
Phys Rev Lett. 2000 May 15;84(20):4521-4. doi: 10.1103/PhysRevLett.84.4521.
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 the critical tunneling current), there is a sharp transition between the dc and ac regimes. The signature is a sudden jump of a large fraction of the relative condensate population. Analytical results are compared with a numerical integration of the Gross-Pitaevskii equation, in an experimentally realistic situation.
我们提出了一个实验，该实验将展示两个弱连接的玻色 - 爱因斯坦凝聚体中的直流和交流约瑟夫森效应。我们考虑一个随时间变化的势垒，它在捕获势中绝热移动。相位动力学由一个“驱动摆”方程控制，就像在电流驱动的超导约瑟夫森结中一样。在势垒的临界速度（与临界隧穿电流成正比）下，直流和交流 regime 之间存在急剧转变。其特征是相对凝聚体粒子数的很大一部分突然跳跃。在实验现实情况下，将解析结果与格罗斯 - 皮塔耶夫斯基方程的数值积分进行了比较。
