Giant intrinsic anomalous terahertz Faraday rotation in the magnetic Weyl semimetal Co2MnGa at room temperature
Giant intrinsic anomalous terahertz Faraday rotation in the magnetic Weyl semimetal Co2MnGa at room temperature
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室温下磁性Weyl半金属Co2MnGa中巨大的本征反常太赫兹法拉第旋转
DOI：
10.1103/physrevb.105.174406
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发表时间：
2022
影响因子：
3.7
通讯作者：
Wu, Liang
中科院分区：
文献类型：
--
作者：
Han, Xingyue;Markou, Anastasios;Stensberg, Jonathan;Sun, Yan;Felser, Claudia;Wu, Liang
我们报告测量太赫兹异常霍尔电导率和法拉第旋转的磁性Weyl半金属薄膜作为磁场，温度和厚度的函数，使用时域太赫兹光谱。在室温下，薄膜的太赫兹电导率与厚度无关，约为600，在0.2-1.5 THz范围内，电导率与频率无关.纵向电导率和霍尔电导率的大小、弱的自旋-轨道耦合以及外尔点与化学势非常接近的位置都满足固有异常霍尔电导率的标准。第一性原理计算也支持低频下的频率无关的本征反常霍尔电导。我们还发现了一个与厚度无关的法拉第旋转，在室温下为59 mrad，这来自于本征Berry曲率的贡献。在最薄的20 nm样品中，由于Berry曲率，法拉第旋转除以样品厚度达到约3 mrad/nm，并且是在室温下报道的最大值。室温下的巨大Verdet常数和在0.2- 1.5THz范围内的大霍尔角表明室温下的THz自旋电子学是有希望的。
We report measurement of terahertz anomalous Hall conductivity and Faraday rotation in the magnetic Weyl semimetalthin films as a function of the magnetic field, temperature, and thickness, using time-domain terahertz spectroscopy. The terahertz conductivity shows a thickness-independent anomalous Hall conductivity of around 600at room temperature, and it is also frequency-independent from 0.2–1.5 THz. The magnitude of the longitudinal and Hall conductivities, the weak spin-orbit coupling, and the very close positioning of Weyl points to the chemical potential all satisfy the criteria for intrinsic anomalous Hall conductivity. First-principles calculation also supports the frequency-independent intrinsic anomalous Hall conductivity at low frequency. We also find a thickness-independent Faraday rotation of 59mrad at room temperature, which comes from the intrinsic Berry curvature contribution. In the thinnest 20 nm sample, the Faraday rotation divided by the sample thickness reaches around 3 mrad/nm due to Berry curvature, and is the largest reported at room temperature. The giant Verdet constant of the order ofradat room temperature and the large Hall angle aroundfrom 0.2–1.5 THz indicate thatis promising for THz spintronics at room temperature.