Spin Hall effect of transmitted light through α-Li3N-type topological semimetals
Spin Hall effect of transmitted light through α-Li3N-type topological semimetals
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透过α-Li3N型拓扑半金属的透射光的自旋霍尔效应
DOI：
10.1039/d1cp04862g
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发表时间：
2022
影响因子：
3.3
通讯作者：
Reza Asgari
中科院分区：
文献类型：
--
作者：
Guangyi Jia;Ruixia Zhang;Ting Tang;Qian Li;Ali Ebrahimian;Zahra Torbati;Reza Asgari
设计了狄拉克半金属 Cd3As2 薄膜上带有 L 形孔图案的手性超表面。通过严格的耦合波分析，研究了温度T对圆转换二色性的影响，其主要特征是圆偏振差分透射率（CPDT）。结果表明，减小T会出现更窄的CPDT峰和谷，通过优化结构参数，在80 K时两相反圆偏振光之间的最大差分透过率可以达到0.60以上。随着T的增加，差分透过率逐渐减小，CPDT峰和谷值分别呈现“Z”型和“S”型变化趋势。推导了CPDT极值相对于T的两个简单公式，预测当T≥500K时，下降趋势将达到饱和。与差分透过率与波长无关的变化趋势不同，随着T的增加，CPDT极值位置在波长λ>10μm(λ<5μm)处主要表现出蓝移(红移)趋势。此外，还清楚地揭示了 CPDT 随 Cd3As2 厚度、入射角和方位角等各种因素的演变。
Chiral metasurfaces patterned with L-shaped holes in a thin film of Dirac semimetal Cd3As2 are designed. The impact of temperature T on circular conversion dichroism, mainly characterized by circular polarization differential transmittance (CPDT), is studied by rigorous coupled-wave analysis. The results show that decreasing T will give rise to the appearance of much more narrow CPDT peaks and dips, and the maximum differential transmittance between two opposite circularly polarized light can reach above 0.60 by optimizing the structural parameters at 80 K. As the T increases, the differential transmittance gradually decreases, and the CPDT peak and dip values exhibit variation tendencies of ‘Z’ and ‘S’ types, respectively. Two simple formulae of CPDT extreme values with respect to T are derived, predicting that the decreasing tendency will reach saturation when T ≥ 500 K. Differing from the wavelength-independent variation trend of differential transmittance, CPDT extremum positions mainly show a blueshift (redshift) tendency at the wavelength λ > 10 μm (λ < 5 μm) as the T increases. Moreover, evolutions of CPDT with various factors including the thickness of Cd3As2, incident and azimuth angles are also clearly unveiled.