Giant tunable nonreciprocity of light in Weyl semimetals
Giant tunable nonreciprocity of light in Weyl semimetals
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DOI：
10.1103/physrevb.98.195446
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发表时间：
2018-08
影响因子：
3.7
通讯作者：
O. Kotov;Y. Lozovik;Yu. E. Lozovik
中科院分区：
文献类型：
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作者：
O. Kotov;Y. Lozovik;Yu. E. Lozovik
分析了光在Weyl半金属薄膜中的传输。这些材料的磁性家族被称为反常霍尔效应，其被大的Berry曲率增强，允许在没有外部磁场的情况下产生强的回旋和非互易效应。预测了在Voigt组态铁磁Weyl半金属薄膜中存在非互易波导电磁模。由于无带隙的外尔谱和大的Berry曲率引起的强介电响应，铁磁外尔半金属联合收割机结合了磁性半导体的最佳波导特性和铁磁体中强的反常霍尔效应。的非互易性的大小取决于两个内部的外尔半金属属性，外尔节点的分离，和外部因素，周围的膜介质之间的光学对比度。通过调节外尔半金属中的费米能级，可以改变太赫兹和中红外范围内波导模式的工作频率。我们的研究结果铺平了道路，紧凑，可调，有效的非互易光学元件的设计。
The propagation of light in Weyl semimetal films is analyzed. The magnetic family of these materials is known by anomalous Hall effect, which, being enhanced by the large Berry curvature, allows one to create strong gyrotropic and nonreciprocity effects without external magnetic field. The existence of nonreciprocal waveguide electromagnetic modes in ferromagnetic Weyl semimetal films in the Voigt configuration is predicted. Thanks to the strong dielectric response caused by the gapless Weyl spectrum and the large Berry curvature, ferromagnetic Weyl semimetals combine the best waveguide properties of magnetic dielectrics or semiconductors with strong anomalous Hall effect in ferromagnets. The magnitude of the nonreciprocity depends both on the internal Weyl semimetal properties, the separation of Weyl nodes, and the external factor, the optical contrast between the media surrounding the film. By tuning the Fermi level in Weyl semimetals, one can vary the operation frequencies of the waveguide modes in THz and mid-IR ranges. Our findings pave the way to the design of compact, tunable, and effective nonreciprocal optical elements.