Nonreciprocal Dyakonov-wave propagation supported by topological insulators
Nonreciprocal Dyakonov-wave propagation supported by topological insulators
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DOI：
10.1364/josab.33.001266
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发表时间：
2016-06
影响因子：
1.9
通讯作者：
T. Mackay;A. Lakhtakia
中科院分区：
文献类型：
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作者：
T. Mackay;A. Lakhtakia
通过数值求解相关的正则边值问题，研究了由柱状薄膜和拓扑绝缘体的平面界面引导的迪亚科诺夫波的传播。拓扑绝缘体被建模为具有非零表面导纳的各向同性介电材料。通过改变表面导纳的大小，可以显着调制迪亚科诺夫波的传播方向以及波的衰减常数和相速度。最重要的是，与沿 -u_ 方向传播的 Dyakonov 波相比，沿矢量 u_ 方向传播的 Dyakonov 波具有不同的相速度和不同的衰减常数。当拓扑绝缘体被具有相同折射率但具有非零表面电导率而不是表面导纳的各向同性电介质材料替代时，这种关于交换迪亚科诺夫波传播方向的非互易性不会表现出来。
The propagation of Dyakonov waves guided by the planar interface of a columnar thin film and a topological insulator was investigated by numerically solving the associated canonical boundary-value problem. The topological insulator was modeled as an isotropic dielectric material endowed with a nonzero surface admittance. The propagation directions for the Dyakonov waves, as well as the decay constants and phase speeds of the waves, were significantly modulated by varying the magnitude of the surface admittance. Most significantly, a Dyakonov wave propagating along the direction of a vector u_ has a different phase speed and different decay constants as compared with the Dyakonov wave which propagates along the direction of −u_. This nonreciprocity, with respect to interchanging the direction of Dyakonov-wave propagation, is not exhibited when the topological insulator is replaced by an isotropic dielectric material of the same refractive index but with a nonzero surface conductivity instead of a surface admittance.