Nonlinear effects in topological materials

作     者：Jack WZUBER Chao ZHANG Jack W.ZUBER;Chao ZHANG

作者机构：School of PhysicsUniversity of WollongongNew South Wales 2522Australia 

出 版 物：《Frontiers of Optoelectronics》 (光电子前沿（英文版）)

年 卷 期：2021年第14卷第1期

页      面：99-109页

核心收录：

学科分类：0808[工学-电气工程] 07[理学] 0809[工学-电子科学与技术（可授工学、理学学位）] 070104[理学-应用数学] 0805[工学-材料科学与工程（可授工学、理学学位）] 0701[理学-数学] 0702[理学-物理学] 

主　　题：terahertz nonlinear effects topological materials Weyl semimetals(WSMs) α-T_(3) systems 

摘      要：Materials,where charge carriers have a linear energy dispersion,usually exhibit a strong nonlinear optical response in the absence of disorder scattering.This nonlinear response is particularly interesting in the terahertz frequency region.We present a theoretical and numerical investigation of charge transport and nonlinear effects,such as the high harmonic generation in topological materials including Weyl semimetals(WSMs)and α-T_(3)systems.The nonlinear optical conductivity is calculated both semi-classically using the velocity operator and quantum mechanically using the density matrix.We show that the nonlinear response is strongly dependent on temperature and topological parameters,such as the Weyl point(WP)separation b and Berry phase ФB.A finite spectral gap opening can further modify the nonlinear effects.Under certain parameters,universal behaviors of both the linear and nonlinear response can be observed.Coupled with experimentally accessible critical field values of 10^(4)-10^(5) V=m,our results provide useful information on developing nonlinear optoelectronic devices based on topological materials.