Disorder Induced Dynamic Equilibrium Localization and Random Phase Steps of Bose–Einstein Condensates
DUAN Ya-Fan1, XU Zhen1, QIAN Jun1, SUN Jian-Fang1, JIANG Bo-Nan1, HONG Tao2**
1Key Laboratory for Quantum Optics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 2Center for Macroscopic Quantum Phenomena, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201203
Disorder Induced Dynamic Equilibrium Localization and Random Phase Steps of Bose–Einstein Condensates
DUAN Ya-Fan1, XU Zhen1, QIAN Jun1, SUN Jian-Fang1, JIANG Bo-Nan1, HONG Tao2**
1Key Laboratory for Quantum Optics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 2Center for Macroscopic Quantum Phenomena, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201203
摘要We numerically analyze the dynamic behavior of Bose–Einstein condensate (BEC) in a one-dimensional disordered potential before it completely loses spatial quantum coherence. We find that both the disorder statistics and the atom interactions produce remarkable effects on localization. We also find that the single phase of the initial condensate is broken into many small pieces while the system approaches localization, showing a counter-intuitive step-wise phase but not a thoroughly randomized phase. Although the condensates as a whole show less flow and expansion, the currents between adjacent phase steps retain strong time dependence. Thus we show explicitly that the localization of a finite size Bose–Einstein condensate is a dynamic equilibrium state.
Abstract：We numerically analyze the dynamic behavior of Bose–Einstein condensate (BEC) in a one-dimensional disordered potential before it completely loses spatial quantum coherence. We find that both the disorder statistics and the atom interactions produce remarkable effects on localization. We also find that the single phase of the initial condensate is broken into many small pieces while the system approaches localization, showing a counter-intuitive step-wise phase but not a thoroughly randomized phase. Although the condensates as a whole show less flow and expansion, the currents between adjacent phase steps retain strong time dependence. Thus we show explicitly that the localization of a finite size Bose–Einstein condensate is a dynamic equilibrium state.
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2011, Vol. 28 
