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arXiv 2505.16331math-phmath.MP
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非量子化自旋输运的广义体-界面对应

Generalized bulk-interface correspondence for non-quantized spin transport

Jiayu Qiu, Hai Zhang

AI总结:

本文建立广义体-界面对应原理,适用于自旋非守恒系统,通过自旋漂移与扭矩电导解释界面自旋输运,并推广了量子化情形下的现有结果。

摘要:

本文为电子系统中可能非守恒的自旋电荷建立了广义体-界面对应(BIC)的严格数学框架,其中哈密顿量与自旋算符不对易。我们首先引入体自旋电导作为体介质的特征,该电导定义为势-流关联函数,若自旋电荷非守恒则不被量子化。随后我们建立BIC原理,该原理指出跨界面的体自旋电导之差等于与沿界面的自旋输运相关的两个量之和:自旋漂移电导(捕捉由界面模式携带的自旋输运)和自旋扭矩电导(解释由于自旋非守恒而在界面附近产生的自旋)。此外,当自旋电荷守恒时,我们的结果恢复基于自旋陈数或Fu-Kane-Mele $\mathbb{Z}_2$指标的现有BIC。我们的发现表明BIC原理不限于具有量子化特征的系统,并为自旋输运现象提供了新的见解。

英文摘要:

This paper establishes a rigorous mathematical framework for a generalized bulk-interface correspondence (BIC) in electronic systems with possibly nonconserved spin charge, where the Hamiltonian and spin operator do not commute. We first introduce the bulk spin conductance as a character of the bulk medium, which is defined as a potential-current correlation function and is not quantized if the spin charge is nonconserved. Then we establish the principle of BIC, which states that the difference of bulk spin conductances across an interface equals the sum of two quantities associated with the spin transport along the interface: the spin-drift conductance, which captures spin transport carried by interface modes, and the spin-torque conductance, which accounts for spin generation near the interface due to the non-conservation of spin. Furthermore, when the spin charge is conserved, our result recovers the existing BIC based on the spin Chern number or Fu-Kane-Mele $\mathbb{Z}_2$ index. Our findings demonstrate that the principle of BIC is not restricted to systems with quantized characters and provides new insights into spin transport phenomena.

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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