【摘要】 研究了对称双势阱玻色-爱因斯坦凝聚体系(BEC)存在均匀噪声或高斯噪声时的自俘获现象.结果发现噪声的存在破坏了自俘获现象的临界行为特征,使得原来约瑟夫森振荡和自俘获之间的临界点变成了一个过渡区域,而且噪声强度越大,这个过渡区域展得越宽.同时发现,对于确定的相互作用强度,当噪声强度增大到一定程度时,相平面会出现混乱,如果这时固定噪声强度增大相互作用强度,相平面中的轨道会重新出现.对纯量子系统加噪声后,自俘获同样不存在临界值,而是存在一个临界区域,且随噪声的增强临界区域会展宽.与平均场近似情况下不同的是,纯量子情况下噪声促进自俘获的产生,且噪声越强自俘获越明显.更多还原

【Abstract】 In this paper we study self-trapping of Bose-Einstein condensates in a symmetric double-well potential with uniform noise or Gaussian noise existing respectively.We find that both uniform noise and Gaussian noise destroy the critical behavior of self-trapping with the interaction increasing and create a transition zone between Josephson oscillation and self-trapping,between which exists a critical point originally.Furthermore,the stronger the noise becomes,the wider the transition zone is.Meanwhile,we find that the phase space falls into complete confusion when we increase noise intensity to a certain extent with interaction fixed,and the trajectories reappear after we increase the interaction without increasing the noise intensity.In the full-quantum situation,when noise exists there is a transition zone instead of a critical value,and stronger noise creates wider transition zone,which is the same as in mean field treatment.What is different is that in full-quantum situation noise creates self-trapping,and the stronger the noise,the more obvious the self-trapping becomes.更多还原