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三维拓扑绝缘体超材料光电效应仿真
Simulation of the photoelectric effect in three-dimensional topological insulator metamaterial
本文提出了一种基于三维拓扑绝缘体Bi1.5Sb0.5Te1.8Se1.2的周期性方环阵列超材料结构。仿真结果表明超材料结构的表面等离子体共振强度随阵列周期和方环内环尺寸的增大而增强，其中，当周期为300 nm或尺寸为25 nm时，可以限制80%的电磁波在表面态上。此外，通过仿真正、斜圆偏振光入射下超材料和非超材料结构的表面电场随偏振态的变化关系，得到了两种结构正、斜入射下的圆二色性。结果表明，超材料结构圆二色性数值为0.92，远大于非超材料结构，并且该超材料结构的圆偏振分量在总偏振光电流分量的占比有显著的提升，这是因为有更多的自旋电子被圆偏振光从拓扑表面态激发到体导带上。
In this paper, a metamaterial structure based on a periodic square-ring array of three-dimensional topological insulators Bi1.5Sb0.5Te1.8Se1.2 is proposed. The simulation results show that the surface plasmon resonance intensity of the metamaterial structure is enhanced with increasing the array period and the size of square ring, where 80% of the electromagnetic wave can be confined to the surface states when the period is 300 nm or the size is 25 nm. In addition, the circular dichroism of the metamaterial and non-metamaterial structures under positive and oblique circularly polarized light incidence are obtained by simulating the relationship between the variation of the surface electric field with the polarization of the metamaterial and non-metamaterial structures under positive and oblique incidence. The circular dichroism of the metamaterial structure of 0.92 is much larger than that of the non-metamaterial structure, and there is a significant increase in the ratio of the circularly polarized component to the total polarized component for this metamaterial structure, which is attributed to the fact that more spintronic electrons are excited by the circularly polarized light from the topological surface state to the body conduction band.
拓扑绝缘体，超材料，圆二色性，表面等离子体共振
topological insulator; metamaterial; circular dichroism; surface plasmon resonance
林宗凯,孙仲恒,杨知霖,周玥,孙逊,俞金玲
LIN Zongkai,SUN Zhongheng,YANG Zhilin,ZHOU Yue,SUN Xun,YU Jinglin
1.福州大学先进制造学院;2.福州大学梅努斯国际工程学院
Menus International College of Engineering,Fuzhou University
bdtgz/article/abstract/20240319001