在横向多层金属异构结构中探测非局部轨道电流的超快THz探测
1Femtosecond Spectroscopy and Nonlinear Photonics Laboratory, Department of Physics, Indian Institute of Technology Delhi, New Delhi, India.
Nature communications
|December 11, 2023
概括
这项研究证明了金属异构结构中的轨道到电荷电流转换,为THz生成铺平了道路. 研究人员解开了自旋和轨道对THz发射的贡献,确定了NiFe/Nb为最强的反轨道霍尔效应.
科学领域:
- 凝聚物质物理学 凝聚物质物理学
- 超快的现象 超快的现象
- 这就是Spintronics.
背景情况:
- 通过五秒钟光激发的自旋式异构结构来产生太赫兹 (THz) 产生对于研究超快自旋传输和充电电流的非侵入性至关重要.
- 对THz生成的轨道自由度的研究仍然是一个欠发达的领域.
研究的目的:
- 在金属异构结构中实验证明轨道到电荷电流转换.
- 解开轨道和旋转自由度对THz发射的贡献.
- 通过轨道运输机制增强THz的产生.
主要方法:
- 制造金属异构结构 (与轻金属或重金属相邻的铁磁层).
- 检测发射的THz脉冲.
- 根据温度进行测量,以分析霍尔电导率.
- 在带有和没有 tungsten 插入的异构结构中THz 排放的比较.
主要成果:
- 在铁磁/金属异构结构中证明了轨道到电荷的电流转换.
- NiFe/Nb表现出最强的反轨道霍尔效应,具有特定的有效内在霍尔导电性.
- CoFeB/Pt显示了反旋转霍尔效应的主要贡献.
- 与CoFeB/W/Ta双层相比,CoFeB/W/Ta异构结构的THz排放量增加了近10倍,这是由于轨道运输的增强造成的.
结论:
- 轨道到充电电流的转换在金属异构结构中是可以实现的,有助于THz的产生.
- 取决于温度的研究有效地区分了轨道和旋转对THz发射的贡献.
- tungsten 插入显著增强 THz 通过轨道运输的排放,为 THz 生产提供了一个新的途径.
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