Nambu-Goldstone modes in segregated Bose-Einstein condensates
Nambu-Goldstone modes in segregated Bose-Einstein condensates
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DOI：
10.1103/physreva.88.043612
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发表时间：
2013-09
影响因子：
2.9
通讯作者：
H. Takeuchi;K. Kasamatsu
中科院分区：
文献类型：
--
作者：
H. Takeuchi;K. Kasamatsu
本文从理论上研究了不互溶双组分玻色-爱因斯坦凝聚体中的Nambu-Goldstone模。在均匀系统中，平坦的畴壁被稳定化，然后垂直于畴壁的平移不变性除了在两个复序参量存在下两个U（1）对称性破缺之外，还自发地破缺。我们阐明了低能激发的性质，并确定存在两种Nambu-Goldstone模：具有线性色散的同相声子和具有分数色散的ripplon。特征色散的签名可以在谐波势中的分离凝聚体中得到验证。
Nambu-Goldstone modes in immiscible two-component Bose-Einstein condensates are studied theoretically. In a uniform system, a flat domain wall is stabilized and then the translational invariance normal to the wall is spontaneously broken in addition to the breaking of two U(1) symmetries in the presence of two complex order parameters. We clarify properties of the low-energy excitations and identify that there exist two Nambu-Goldstone modes: in-phase phonon with a linear dispersion and ripplon with a fractional dispersion. The signature of the characteristic dispersion can be verified in segregated condensates in a harmonic potential.