title: Off-diagonal long-range order in Bose liquids: irrotational flow and quantization of circulation.
abstract: On the basis of gauge invariance, it is proven in an elementary and straightforward manner, but without invoking any ad hoc assumption, that the existence of off-diagonal long-range order in one-particle reduced density matrix in Bose liquids implies both the irrotational flow in a simply connected region and the quantization of circulation in a multiply connected region, the two fundamental properties of a Bose superfluid. The origin for both is the phase coherence of condensate wave functions. Some relevant issues are also addressed.
authors: Department of Physics, Graduate School at Beijing, University of Science and Technology of China, Chinese Academy of Sciences, P.O. Box 3908, Beijing 100039, China. gsu@cc6.gsbustc.ac.cn
authors: G
authors: G
authors: Su
authors: M
authors: M
authors: Suzuki