Instabilities of Bose-Einstein condensates in optical lattices

CCUR > College of Natural Science and Engineering > College of Science > Department of Physics > journal articles > Item 987654321/2689

Please use this identifier to cite or link to this item: https://irlib.pccu.edu.tw/handle/987654321/2689

Title:	Instabilities of Bose-Einstein condensates in optical lattices
Authors:	Kuan, W. H.;Jiang, T. F.;Cheng, Szu-Cheng
Contributors:	物理系
Date:	2007
Issue Date:	2009-11-13 15:07:36 (UTC+8)
Abstract:	We study the instabilities, Landau and dynamical instabilities, that are two mechanisms responsible for the breakdown of superfluidity in Bose-Einstein condensates interacting with a one-dimensional optical lattice. An effective-mass Gross-Pitaevskii equation was used to calculate the excitation spectrum and the condensate density of Bose-Einstein condensates in a weak periodic potential. After the condensate velocities greater than the speed of sound, we observe a decreasing of the condensate density, which is the onset of Landau instability. The condensate is dissipated, but not completely, from colliding with the thermal atom cloud. For even higher velocities of the condensate, we find a fast decreasing of the condensate density until full removal of the condensate. The regime of totally removing of the condensate is happened at the inverse effective mass of the condensate becoming zero or negative, where the condensate is on the dynamical instability.
Relation:	CHINESE JOURNAL OF PHYSICS Volume: 45 Issue: 2 Pages: 219-229 Part: Part 2
Appears in Collections:	[Department of Physics ] journal articles

Files in This Item:

There are no files associated with this item.