摘要
利用博戈留波夫方法计算了流动状态下玻色系统的准粒子激发谱,根据色散关系的正定性要求给出了超流的稳定性条件.当体系具有伽利略不变性时,该条件即等价于通常的朗道判据.通过具体模型的实例,分别计算了在伽利略不变性被满足与被破坏两种不同情形下的超流临界速度.
Quasi-particle excitations in a bosonic superfluid are calculated via Bogoliubov approach for a general Hamiltonian.The stability condition for superfluidity is derived according to the requirement that the energy disper-sion be definite positive.Such a condition is equivalent to Landau criterion when the system is Galilean invariant. The critical velocity of the superfluid is obtained for the specific models in which Galilean invariance is either satis-fied or violated.
出处
《江苏科技大学学报（自然科学版）》
CAS
2014年第2期201-204,共4页
Journal of Jiangsu University of Science and Technology:Natural Science Edition
基金
江苏科技大学苏州理工学院2014青年教师科研专项基金(128111404)
关键词
超流
临界速度
朗道判据
superfluidity
critical velocity
Landau criterion
