The anisotropy of a trap potential can impact the density and variance of a Bose-Einstein condensate (BEC) in an opposite manner. We exemplify this effect for both the ground state and out-of-equilibrium dynamics of structureless bosons interacting by a long-range inter-particle interaction and trapped in a two-dimensional single-well potential. We demonstrate that even when the density of the BEC is, say, wider along the y direction and narrower along the x direction, its position variance can actually be smaller and momentum variance larger in the y direction than in the x direction. This behavior of the variance in a many-particle system is counterintuitive. It suggests using the variance as a tool to characterize the strength of correlations along the y and x directions in a trapped BEC.
Bibliographical noteFunding Information:
This paper is dedicated to Professor Hans-Dieter Meyer, a dear colleague and friend, on the occasion of his 70th birthday. This research was supported by the Israel Science Foundation (Grant No. 600/15 ). Partial financial support by the Deutsche Forschungsgemeinschaft (DFG) is acknowledged. We thank Kaspar Sakmann for discussions. Computation time on the Cray XC40 system Hazelhen at the High Performance Computing Center Stuttgart (HLRS) is gratefully acknowledged. Appendix A
© 2018 Elsevier B.V.
ASJC Scopus subject areas
- Physics and Astronomy (all)
- Physical and Theoretical Chemistry