雪茄形铷原子玻色-爱因斯坦凝聚中单极子模的朗道阻尼和频移  

Landau damping and frequency-shift of monopole mode in an elongated-rubidium Bose-Einstein condensate

作　　者：柴兆亮[1] 周昱[2] 马晓栋[1] 

机构地区：[1]新疆师范大学物理与电子工程学院,乌鲁木齐830054 [2]江苏科技大学数理学院,镇江212003 Xinjiang Normal Univ, Coll Phys & Elect Engn, Urumqi 830054, Peoples R China; Jiangsu Univ Sci & Technol, Sch Math & Phys, Zhenjiang 212003, Peoples R China

出　　处：《物理学报》2013年第13期92-99,共8页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:10864006;11047101;11264039;11205071);新疆高校科研计划重点项目(批准号:XJED2010141);新疆理论物理重点学科(批准号:LLWLY201106;LLWLY201107);新疆师范大学研究生科技创新项目(批准号:20111202;20121214)资助的课题~~

摘　　要：采用含时哈特里-福克-博戈留波夫近似研究雪茄形铷原子玻色-爱因斯坦凝聚中单极子模的朗道阻尼和频移.通过考虑元激发的实际弛豫及其各弛豫间的正交关系改进原有方法,并由此给出计算朗道阻尼和频移的新公式.此外,令凝聚体边界处动能密度为零代替令基态能量极小以改进原消除三模耦合矩阵元的方法.通过这些改进,同时计算阻尼和频移,并讨论它们的温度依赖,所得理论结果都与实验符合.The Landau damping and frequency-shift of monopole mode in an elongated-rubidium Bose-Einstein condensate are investigated by using the time-dependent Hartree-Fock-Bogoliubov approximation. Improving the previous approach, We have taken into account the practical relaxations of elementary excitations and the orthogonal relation among them. With such an approach, we provide a new calculation formula for Landau damping rate and frequency-shift. In addition, our previous method of eliminating the divergence in three-mode coupling matrix elements is also improved by zeroing the kinetic energy at the condensate boundary instead of minimizing the ground-state energy. Based on these improvements, both the Landau damping rate and the frequency-shift of the monopole mode are analytically calculated and their temperature dependences are also discussed. And all the theoretical results are in agree meat with experimental data.

关 键 词：玻色-爱因斯坦凝聚 朗道阻尼和频移 哈特里-福克-博戈留波夫近似 托马斯-费米近似 

分 类 号：O431.2[机械工程—光学工程]