arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1706.09030cond-mat.mes-hallcond-mat.str-el
收藏

耦合量子自旋链隧穿自旋流中的噪声

Noise in tunneling spin current across coupled quantum spin chains

Joshua Aftergood, So Takei

摘要:

我们从理论上研究了自旋电流和直流噪声之间产生的两个自旋-1/2自旋链弱耦合在一个单一的网站在存在一个过度人口的自旋激发和相对于其他子系统的温度升高,并比较相应的输运量在两个弱耦合磁绝缘体托管磁振子。在自旋链的情况下,我们发现,施加一个温度偏置专门导致一个消失的自旋电流和随之而来的发散的自旋Fano因子,定义为自旋电流噪声信号比。这种分歧被证明有一个确切的类比的物理之间的电子散射分数量子霍尔边缘状态,而不是出现在磁振子的情况。我们还揭示了抑制自旋电流噪声,专门出现在自旋链的情况下,由于费米子性质的自旋1/2运营商。我们讨论了如何通过反自旋霍尔效应在自旋电子学中广泛使用的实验提取自旋Fano因子。

英文摘要:

We theoretically study the spin current and its dc noise generated between two spin-1/2 spin chains weakly coupled at a single site in the presence of an over-population of spin excitations and a temperature elevation in one subsystem relative to the other, and compare the corresponding transport quantities across two weakly coupled magnetic insulators hosting magnons. In the spin chain scenario, we find that applying a temperature bias exclusively leads to a vanishing spin current and a concomitant divergence in the spin Fano factor, defined as the spin current noise-to-signal ratio. This divergence is shown to have an exact analogy to the physics of electron scattering between fractional quantum Hall edge states and not to arise in the magnon scenario. We also reveal a suppression in the spin current noise that exclusively arises in the spin chain scenario due to the fermion nature of the spin-1/2 operators. We discuss how the spin Fano factor may be extracted experimentally via the inverse spin Hall effect used extensively in spintronics.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑