论文标题
电子光束在拓扑绝缘体表面状态下分裂，并提出电子鹅横幅测量的建议
Electron beam splitting at topological insulator surface states and a proposal for electronic Goos-Hanchen shift measurement
论文作者
论文摘要
理论上研究了对具有潜在屏障的拓扑绝缘子表面上电子的转速扭曲作用，以及电子在拓扑绝缘子表面上的侧向横向移位。由于入射电子束的扭曲的费米表面，我们可以期望两个传播的传播光束对应于双重折射。传输的梁具有锁定到其动量的旋转方向，因此与入射自旋方向相比，其中一个自旋方向旋转。基于迪拉克点附近的低能哈密顿量并考虑高斯梁，我们得出了在存在翘曲效果的情况下计算横向移位的表达式。我们通过解释了与其传输峰相对应的横向移位中的大峰出现，从而详细研究了传输梁对系统参数的依赖性。结果表明，两个通过其不同的GH偏移的传输梁之间的分离可以与几微米一样大，这足够大，可以在实验中观察到。最后，我们提出了一种基于横向磁焦点技术测量电子束移动的方法，在这种技术中，通过调整施加的磁场，可以诱导可检测到的电子谐振路径。
The hexagonal warping effect on transport properties and Goos-Hänchen (GH) lateral shift of electrons on the surface of a topological insulator with a potential barrier is investigated theoretically. Due to the warped Fermi surface for incident electron beams, we can expect two propagating transmitted beams corresponding to the occurrence of double refraction. The transmitted beams have spin orientations locked to their momenta so one of the spin directions rotates compared to the incident spin direction. Based on a low-energy Hamiltonian near the Dirac point and considering Gaussian beams, we derive expressions for calculating lateral shifts in the presence of warping effect. We study the dependence of transmission probabilities and GH shifts of transmitted beams on system parameters in detail by giving an explanation for the appearance of large peaks in the lateral shifts corresponding to their transmission peaks. It is shown that the separation between two transmitted beams through their different GH shifts can be as large as a few micrometers, which is large enough to be observed experimentally. Finally, we propose a method to measure the GH shift of electron beams based on the transverse magnetic focusing technique in which, by tuning an applied magnetic field, a detectable resonant path for electrons can be induced.
