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arXiv 2409.09669cond-mat.mes-hall
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时间变化电场内在动态产生自旋极化

Intrinsic Dynamic Generation of Spin Polarization by Time-Varying Electric Field

Xukun Feng, Jin Cao, Zhi-Fan Zhang, Lay Kee Ang, Shen Lai, Hua Jiang, Cong Xiao, Shengyuan A. Yang

AI总结:

本文提出时间变化电场驱动绝缘体中动态自旋产生的内在效应,基于贝里曲率机制,预测太赫兹场在非磁性单层Bi和反铁磁MnBi$_2$Te$_4$中产生可观自旋极化,可用于低功耗超快自旋电子学。

摘要:

在绝缘体中实现自旋的电控是低功耗和超快自旋电子学的理想目标,但其潜在机制在很大程度上仍未得到探索。在此,我们提出了一种由时间变化电场驱动的动态自旋产生的内在效应。在带内响应机制下,它可以很好地表述为贝里曲率效应,并导致两种在直流极限下被禁止的现象:非磁性绝缘体中的线性自旋产生和$\mathcal{PT}$对称反铁磁绝缘体中的内在Néel自旋轨道矩。这些现象由场的时间导数而非场本身驱动,其量子起源在于一阶动态反常自旋极化率。结合第一性原理计算,我们预测了太赫兹场在非磁性单层Bi和反铁磁偶数层MnBi$_2$Te$_4$中驱动的可观效应,这些效应可以在实验中检测到。

英文摘要:

Electric control of spin in insulators is desired for low-consumption and ultrafast spintronics, but the underlying mechanism remains largely unexplored. Here, we propose an intrinsic effect of dynamic spin generation driven by time-varying electric field. In the intraband response regime, it can be nicely formulated as a Berry curvature effect and leads to two phenomena that are forbidden in the $dc$ limit: linear spin generation in nonmagnetic insulators and intrinsic N{é}el spin-orbit torque in $\mathcal{PT}$-symmetric antiferromagnetic insulators. These phenomena are driven by the time derivative of field rather than the field itself, and have a quantum origin in the first-order dynamic anomalous spin polarizability. Combined with first-principles calculations, we predict sizable effects driven by terahertz field in nonmagnetic monolayer Bi and in antiferromagnetic even-layer MnBi$_2$Te$_4$, which can be detected in experiment.

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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