论文标题
拓扑绝缘体表面状态的三阶霍尔效应
Third-order Hall effect in the surface states of a topological insulator
论文作者
论文摘要
时间逆转和反转对称材料无法产生线性和非线性响应,因为它们具有零浆果曲率。但是,在约束晶体对称性的情况下,可以在这些系统中产生高阶HALL响应。由最近发现的三阶大厅(TOH)响应介导的动机是由贝瑞连接极化性介导的,即,在六角形扭曲拓扑绝缘子的表面状态下,浆果连接相对于应用的电场的变化,仅在电力领域的六角形扭曲拓扑绝缘体(例如BI $ _2 $ _3 $ _3 $)中存在。使用半古典玻尔兹曼形式主义,我们研究了倾斜和六角形翘曲对浆果连接极化张量的影响,因此,只要狄拉克锥保持无间隙,就会效果。我们发现,随着倾斜强度和翘曲的增加,响应的幅度显着增加,因此,它们可以提供这种效果的可调节性。此外,我们还探讨了化学掺杂对该系统中TOH响应的影响。有趣的是,我们基于对称分析表明,TOH可以是该系统中可以直接验证实验中的领先响应。
Time reversal and inversion symmetric materials fail to yield linear and nonlinear responses since they possess net zero Berry curvature. However, higher-order Hall response can be generated in these systems upon constraining the crystalline symmetries. Motivated by the recently discovered third-order Hall (TOH) response mediated by Berry connection polarizability, namely, the variation the Berry connection with respect to an applied electric field, here we investigate the existence of such Hall effect in the surface states of hexagonal warped topological insulator (e.g., Bi$_2$Te$_3$) under the application of electric field only. Using the semiclassical Boltzmann formalism, we investigate the effect of tilt and hexagonal warping on the Berry connection polarizability tensor and consequently, the TOH effect provided the Dirac cone remains gapless. We find that the magnitude of the response increases significantly with increasing the tilt strength and warping and therefore, they can provide the tunability of this effect. In addition, we also explore the effect of chemical doping on TOH response in this system. Interestingly, we show based on the symmetry analysis, that the TOH can be the leading-order response in this system which can directly be verified in experiments.