Superfluidity of Bose-Einstein condensates in toroidal traps with nonlinear lattices
Superfluidity of Bose-Einstein condensates in toroidal traps with nonlinear lattices
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DOI：
10.1103/physreva.84.063638
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发表时间：
2011-12
影响因子：
2.9
通讯作者：
A. Yulin;Y. Bludov;V. Konotop;V. Kuzmiak;M. Salerno
中科院分区：
文献类型：
--
作者：
A. Yulin;Y. Bludov;V. Konotop;V. Kuzmiak;M. Salerno
研究了在环形准一维势阱中存在沿环沿着的周期性散射长度调制时玻色-爱因斯坦凝聚（BEC）的超流性质。几种类型的稳定的周期波的存在，范围从几乎均匀的弱相互作用和等距孤立子的非常破碎的链，证明。我们表明，这些波可以支持持久的原子电流和声波的光谱Bogoliubov型。碎裂的凝聚体可以被看作是约瑟夫森结的阵列，电流可以看作是直流约瑟夫森效应的BEC表现。线性缺陷对BEC超流性的影响也进行了研究。我们发现，对于亚临界速度，线性缺陷是静态的相对于晶格（而冷凝物移动相对于光学晶格和缺陷）保存BEC超流性。
Superfluid properties of Bose-Einstein condensates (BEC) in toroidal quasi-one-dimensional traps are investigated in the presence of periodic scattering length modulations along the ring. The existence of several types of stable periodic waves, ranging from almost uniform to very fragmented chains of weakly interacting and equally spaced solitons, is demonstrated. We show that these waves may support persistent atomic currents and sound waves with spectra of Bogoliubov type. Fragmented condensates can be viewed as arrays of Josephson junctions and the current as a BEC manifestation of the dc-Josephson effect. The influence of linear defects on BEC superfluidity has been also investigated. We found that for subcritical velocities, linear defects that are static with respect to the lattice (while the condensate moves in respect to both the optical lattice and the defect) preserve the BEC superfluidity.