Acta Physica Sinica
Phase transition and entanglement entropy of Bose-Einstein condensates in double-well trap under periodic modulation
Fang Yong-Cui, Yang Zhi-An, Yang Li-Yun, (1)北京应用物理与计算数学研究所,北京 100088; (2)济南大学理学院,济南 250022
Abstract
Dynamical phase transition of Bose-Einstein condensates (BEC) in double-well trap with external periodic modulation applied to the interaction term is investigated in this paper. Particularly, phase transition to chaos is studied. It is found that, when resonance between the modulation frequency and the natural frequency of the system happens, the system turns to instability (chaos) at certain values of the parameters. In the chaotic region, distribution of particles is random, and the average of population difference fluctuates around zero. Especially, chaos can be manifested by the entanglement entropy. In the chaotic zone, both of the average entanglement entropies approach to their maxima.