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超快的爱因斯坦-德哈斯效应

C Dornes¹, Y Acremann², M Savoini³

¹Institute for Quantum Electronics, Physics Department, ETH Zurich, Zurich, Switzerland. dornesc@phys.ethz.ch.

|January 4, 2019

概括

在超快速去磁化中,激光诱导的铁的旋转角动量损失在200 femtosecond内转移到网格中,发射一个应变波. 这揭示了晶格相互作用在秒消磁动态中的关键作用.

科学领域:

凝聚物质物理
超快磁性
旋转动力学

背景情况:

爱因斯坦-德哈斯效应证明了旋转到机械的角动量转换.
超快速去磁包括光激发时<100 fs的磁化损失.
超快解磁过程中的角动量命运尚未完全理解.

研究的目的:

研究激光诱导脱磁过程中角动量转移的时间范围和机制.
确定旋转角动量在 femtosecond 时间尺度上转移的位置.

主要方法:

用5秒时间的X射线衍射探测铁.
分析包括将实验X射线数据与模拟和光学数据相匹配.

主要成果:

大多数自旋角动量在去磁化过程中被转移到子皮秒时间尺度内的晶格中.
一个横向的应变波被发射到散装材料中.
角动量转移发生在200秒的时间尺度上,占自旋角动量的80%.

结论:

网格相互作用在超快的去磁化中起着至关重要的作用.
这些发现阐明了在五秒钟消磁过程中角动量转移的微观机制.

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