Unusual behavior of sound velocity of a Bose gas in an optical superlattice at quasi-one-dimension

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	Unusual behavior of sound velocity of a Bose gas in an optical superlattice at quasi-one-dimension
	L.; Chen Chen, Z.; Li, W.; Zhang, Z. D.; Liang, Z. X.
	2014
发表期刊	European Physical Journal D
ISSN	1434-6060
卷号	68 期号:12
摘要	A Bose gas trapped in a one-dimensional optical superlattice has emerged as a novel superfluid characterized by tunable lattice topologies and tailored band structures. In this work, we focus on the propagation of sound in such a novel system and have found new features on sound velocity, which arises from the interplay between the two lattices with different periodicity and is not present in the case of a condensate in a monochromatic optical lattice. Particularly, this is the first time that the sound velocity is found to first increase and then decrease as the superlattice strength increases even at one dimension. Such unusual behavior can be analytically understood in terms of the competition between the decreasing compressibility and the increasing effective mass due to the increasing superlattice strength. This result suggests a new route to engineer the sound velocity by manipulating the superlattice's parameters. All the calculations based on the mean-field theory are justified by checking the exponent gamma of the off-diagonal one-body density matrix that is much smaller than 1. Finally, the conditions for possible experimental realization of our scenario are also discussed.
部门归属	[chen, lei ; li, wu ; zhang, zhidong ; liang, zhaoxin] chinese acad sci, inst met res, shenyang natl lab mat sci, shenyang 110016, peoples r china. [chen, zhu] inst appl phys & computat math, natl key lab sci & technol computat phys, beijing 100088, peoples r china. ; chen, l (reprint author), chinese acad sci, inst met res, shenyang natl lab mat sci, wenhua rd 72, shenyang 110016, peoples r china. ; zhxliang@imr.ac.cn
关键词	Einstein Condensate Elementary Excitations Ultracold Gases Bloch Bands Cold Atoms Dynamics Lattice Propagation Confinement Speed
URL	查看原文
语种	英语
文献类型	期刊论文
条目标识符	http://ir.imr.ac.cn/handle/321006/73771
专题	中国科学院金属研究所
推荐引用方式 GB/T 7714	L.,Chen Chen, Z.,Li, W.,et al. Unusual behavior of sound velocity of a Bose gas in an optical superlattice at quasi-one-dimension[J]. European Physical Journal D,2014,68(12).
APA	L.,Chen Chen, Z.,Li, W.,Zhang, Z. D.,&Liang, Z. X..(2014).Unusual behavior of sound velocity of a Bose gas in an optical superlattice at quasi-one-dimension.European Physical Journal D,68(12).
MLA	L.,et al."Unusual behavior of sound velocity of a Bose gas in an optical superlattice at quasi-one-dimension".European Physical Journal D 68.12(2014).