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在金属表面上引发电流的圆形二重化:一项第一原则研究

Farzad Mahfouzi^1,2, Mark D Stiles¹, Paul M Haney¹

¹Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA.

Physical review. B

|February 19, 2025

概括

在金属薄膜中的电流诱导的光学响应是使用ab initio计算来评估的. 结果揭示了自旋轨道磁化和以原子为中心的近似轨道时刻之间的显著差异,影响了光学测量解释.

科学领域:

凝聚物质物理学凝聚物质物理学
材料科学材料科学材料科学
计算物理计算物理

背景情况:

轨道磁化和金属薄膜中的电流诱导的光学反应对于自旋电子设备至关重要.
光学吸收和轨道磁化之间的关系是由总和规则描述的,特别是涉及自旋贡献.
原子中心近似 (ACA) 通常用于计算轨道运动积累.

研究的目的:

用ab initio计算来评估金属薄膜表面的电流诱导的光学响应和轨道时刻积累.
为了比较轨道磁化 ( ${\vec{M}}_{SR}) 的标尺不变自旋贡献与 ACA 轨道运动积累.$
调查有限尺寸效应和层厚对这些数量的影响.

主要方法:

使用初始计算来模拟金属薄膜表面.
计算电流诱导的光学响应和轨道时刻积累.
计算了尺度不变的自旋贡献 ( ${\vec{M}}_{SR}) 并将其与以原子为中心的近似方法 (ACA) 进行了比较.$

主要成果:

在M→SR和ACA轨道时刻积累之间发现了显著的差异,M→SR是一个更大的数量级.
在计算的 ${\vec{M}}_{SR} 中观察到实质性的有限尺寸效应,用于Pt薄膜.$
确定表面积累的和长度尺度是 $\vec{M} SR 和ACA的平均自由路径的顺序.$

结论:

M→SR和ACA之间的差异突出了ACA模型在解释光学测量的局限性.
结果表明M→SR提供了对电流诱导的轨道磁化的更全面的描述.
这项研究强调了在表面磁性的理论模型中考虑有限尺寸效应和层厚的重要性.

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