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arXiv 0802.0348cond-mat.mes-hall
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热影响产生的热自旋霍尔效应与thermoelectric effect

Thermospin Hall effect generated by thermal influence and thermoelectric effect

Zhongshui Ma

摘要:

本文提出了热自旋霍尔效应的理论预言,即在存在自旋轨道耦合的半导体中,由随频率变化的纵向温度梯度产生横向自旋电流。由于热电效应,不存在净充电电流,但存在从热侧到冷侧的热流。本文对二维Rashba自旋电子系统的动态热自旋霍尔电导率进行了理论计算。结果表明,直接带间光学跃迁在横向内禀自旋流的产生中主导着自旋的有序化和操纵。根据热电效应的作用,将热自旋霍尔效应的贡献分为热电子扩散的直接贡献和与热扩散平衡的补偿电子流的贡献。对于一个有限的系统,分析产生的证据表明,自旋积累周围的边缘板确定的磁化。在平衡状态下,由磁化梯度产生的场沿垂直于温度梯度的方向出现。通过测量注入横向自旋电流时的纵向温差和分析霍尔角,提出了热自旋霍尔效应的实验观测。此外,为了实现自旋霍尔效应中的纯自旋积累,提出了热自旋霍尔效应用于激发半导体中的电子-空穴对的扩展。

英文摘要:

In this paper, we present the theoretical predication of a thermospin Hall effect, in which a transverse spin current can be generated in semiconductors in the presence of spin-orbit coupling by a frequency-dependent longitudinal temperature gradient. Because of the thermoelectric effect, there is no net charge current but there is a heat flow from the hot side to the cold side. We perform the theoretical calculation of dynamical thermospin Hall conductivity in a two-dimensional Rashba spintronic system. It has been shown that the direct interband optical transition dominates the ordering and manipulation of spin in the generation of a transverse intrinsic spin current. In view of the role of the thermoelectric effect, the contributions to the thermospin Hall effect are classified as that originating from a direct contribution of thermal electronic diffusion and that from the compensatory electron flow in balance with the thermal diffusion. For a finite system, the analysis yields evidence that the spin accumulation around the edges of a plate determines the magnetization. In equilibrium, a field created by a magnetization gradient emerges in the direction perpendicular to the temperature gradient. The experimental observation of the thermospin Hall effect is proposed by measuring the longitudinal temperature difference with the injection of a transverse spin current and by analyzing the Hall angle. In addition, in order to achieve pure spin accumulation in the spin Hall effect, an extension of the thermospin Hall effect for exciting electron-hole pairs in semiconductors is proposed.

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。

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