Extrinsic Nonlinear Kerr Rotation in Topological Materials under a Magnetic Field.
Extrinsic Nonlinear Kerr Rotation in Topological Materials under a Magnetic Field.
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DOI：
10.1021/acsnano.3c04153
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发表时间：
2023-09
期刊：
影响因子：
17.1
通讯作者：
Shuang Wu;Z. Fei;Zeyuan Sun;Yangfan Yi;W. Xia;Dayu Yan;Yanfeng Guo;Youguo Shi;Jiaqiang Yan;D. Cobden;Wei-Tao Liu;Xiaodong Xu;Shiwei Wu
中科院分区：
文献类型：
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作者：
Shuang Wu;Z. Fei;Zeyuan Sun;Yangfan Yi;W. Xia;Dayu Yan;Yanfeng Guo;Youguo Shi;Jiaqiang Yan;D. Cobden;Wei-Tao Liu;Xiaodong Xu;Shiwei Wu
量子材料的拓扑性质通常受对称性的影响，并受晶体结构和外场的影响，因此，磁场中的非线性光学测量是一种很有价值的探索。在这里，我们报告的非线性磁光二次谐波产生（SHG）的拓扑材料，包括双层WTe 2，单层WSe 2，和散装钽砷的研究。磁场下的光学二次谐波的偏振分辨图案显示在这些时间反演对称材料的非线性克尔旋转。对于具有3重旋转对称晶格结构的材料，SHG偏振图案在磁场中仅轻微旋转，而在具有镜像或2重旋转对称的材料中，SHG偏振图案旋转很大并且失真。这些不同的磁倍频特性可以通过考虑磁场诱导的非时不变非线性光学张量和基于晶体结构的非时不变对应物的叠加来理解。通过仔细研究法拉第旋转，其微妙的相互作用与晶体对称性的不同行为的外在非线性克尔旋转在不同的材料帐户的情况进一步澄清。我们的工作说明了磁SHG技术在直接探测非平凡拓扑性质方面的应用，并强调了在偏振分辨磁光研究中最小化非线性克尔旋转的重要性。
Topological properties in quantum materials are often governed by symmetry and tuned by crystal structure and external fields, and hence, symmetry-sensitive nonlinear optical measurements in a magnetic field are a valuable probe. Here, we report nonlinear magneto-optical second harmonic generation (SHG) studies of nonmagnetic topological materials including bilayer WTe2, monolayer WSe2, and bulk TaAs. The polarization-resolved patterns of optical SHG under a magnetic field show nonlinear Kerr rotation in these time-reversal symmetric materials. For materials with 3-fold rotational symmetric lattice structure, the SHG polarization pattern rotates just slightly in a magnetic field, whereas in those with mirror or 2-fold rotational symmetry, the SHG polarization pattern rotates greatly and distorts. These different magneto-SHG characters can be understood by considering the superposition of the magnetic field-induced time-noninvariant nonlinear optical tensor and the crystal-structure-based time-invariant counterpart. The situation is further clarified by scrutinizing the Faraday rotation, whose subtle interplay with crystal symmetry accounts for the diverse behavior of the extrinsic nonlinear Kerr rotation in different materials. Our work illustrates the application of magneto-SHG techniques to directly probe nontrivial topological properties, and underlines the importance of minimizing extrinsic nonlinear Kerr rotation in polarization-resolved magneto-optical studies.