Quantum enhancement of spin drag in a Bose gas
Quantum enhancement of spin drag in a Bose gas
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DOI：
10.1088/1367-2630/17/11/113026
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发表时间：
2015-11
影响因子：
3.3
通讯作者：
S. Koller;A. Groot;P. Bons;R. Duine;H. Stoof;P. Straten
中科院分区：
文献类型：
--
作者：
S. Koller;A. Groot;P. Bons;R. Duine;H. Stoof;P. Straten
在自旋电子学中，研究了固态系统中自旋电流的主动控制和操纵。与电荷电流相反，自旋电流由于不同自旋载流子之间的碰撞以及杂质和晶格振动引起的弛豫而受到强烈的阻尼。自旋电流的松弛现象称为自旋阻力。本文研究了超冷玻色子原子中的自旋阻力，发现自旋阻力是该系统中自旋电流的主要阻尼机制。通过增加相空间密度，我们发现由于玻色刺激，自旋阻力在量子态中增加了两倍以上，这与最近的理论预测一致，令人惊讶的是，在相变以上已经发生了相当大的变化。
In spintronics the active control and manipulation of spin currents is studied in solid-state systems. Opposed to charge currents, spin currents are strongly damped due to collisions between different spin carriers in addition to relaxation due to impurities and lattice vibrations. The phenomenon of relaxation of spin currents is called spin drag. Here we study spin drag in ultra-cold bosonic atoms deep in the hydrodynamic regime and show that spin drag is the dominant damping mechanism for spin currents in this system. By increasing the phase space density we find that spin drag is enhanced in the quantum regime by more than a factor of two due to Bose stimulation, which is in agreement with recent theoretical predictions and, surprisingly, already occurs considerably above the phase transition.