Comment on ``Nonlinear band structure in Bose-Einstein condensates: Nonlinear Sch\"odinger equation with a Kronig Penney potential"
Other Condensed Matter
2009-11-13 v2
Abstract
In their recent paper [Phys. Rev. A 71, 033622], B. T. Seaman et al. studied Bloch states of the condensate wave function in a Kronig-Penney potential and calculated the band structure. They argued that the effective mass is always positive when a swallow-tail energy loop is present in the band structure. In this comment, we reexamine their argument by actually calculating the effective mass. It is found that there exists a region where the effective mass is negative even when a swallow-tail is present. Based on this fact, we discuss the interpretation of swallow-tails in terms of superfluidity.
Keywords
Cite
@article{arxiv.cond-mat/0703045,
title = {Comment on ``Nonlinear band structure in Bose-Einstein condensates: Nonlinear Sch\"odinger equation with a Kronig Penney potential"},
author = {Ippei Danshita and Shunji Tsuchiya},
journal= {arXiv preprint arXiv:cond-mat/0703045},
year = {2009}
}
Comments
3 pages, 3 figures