Spin diffusion in trapped gases: Anisotropy in dipole and quadrupole modes
Spin diffusion in trapped gases: Anisotropy in dipole and quadrupole modes
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捕获气体中的自旋扩散：偶极和四极模式中的各向异性
DOI：
10.1103/physreva.74.043607
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发表时间：
2006
期刊：
影响因子：
--
通讯作者：
R. Ragan
中科院分区：
文献类型：
--
作者：
W. Mullin;R. Ragan
最近的实验在两个超精细态的玻色气体的混合物中显示出类似于自旋（1/2）系统的行为，包括横向自旋波和其他熟悉的莱格特-赖斯型效应。我们推导出适用于这些系统的动力学方程，包括碰撞积分中粒子间相互作用的自旋依赖性，并求解了玻尔兹曼极限中的自旋波频率和纵向和横向扩散常数。我们发现，虽然被困费米气体的横向和纵向碰撞时间是相同的，玻色气体显示出不寻常的扩散各向异性在偶极和四极模式。此外，自旋各向同性的相互作用的缺乏导致横自旋的不守恒，这反过来又有显着的影响的流体动力学模式。
Recent experiments in a mixture of two hyperfine states of trapped Bose gases show behavior analogous to a spin-(1/2) system, including transverse spin waves and other familiar Leggett-Rice-type effects. We have derived the kinetic equations applicable to these systems, including the spin dependence of interparticle interactions in the collision integral, and have solved for spin-wave frequencies and longitudinal and transverse diffusion constants in the Boltzmann limit. We find that, while the transverse and longitudinal collision times for trapped Fermi gases are identical, the Bose gas shows unusual diffusion anisotropy in both dipole and quadrupole modes. Moreover, the lack of spin isotropy in the interactions leads to the nonconservation of transverse spin, which in turn has significant effects on the hydrodynamic modes.