论文标题
在三维二阶拓扑绝缘子中对铰链状态的有限尺寸影响
Finite size effects on hinge states in three-dimensional second-order topological insulators
论文作者
论文摘要
我们研究了具有四倍旋转对称性和时间反向对称性的三维二阶拓扑绝缘子的有限尺寸效应。从三维二阶拓扑绝缘子的有效哈密顿量开始，我们得出了四个二维表面状态的有效哈密顿量，其间隙通过扰动方法得出。然后，有效的哈密顿量在相邻表面上的质量术语的符号交替导致铰链状态。此外，我们基于二维表面状态的有效哈密顿量，我们获得了有效的哈密顿量及其具有半侵占边界条件的一维无间隙状态的波功能。特别是，我们发现同一表面两侧的铰链状态可能会产生有限的能隙。
We investigate the finite size effects of a three-dimensional second-order topological insulator with fourfold rotational symmetry and time-reversal symmetry. Starting from the effective Hamiltonian of the three-dimensional second-order topological insulator, we derive the effective Hamiltonian of four two-dimensional surface states with gaps derived by perturbative methods. Then, the sign alternation of the mass term of the effective Hamiltonian on the adjacent surface leads to the hinge state. In addition, we obtain the effective Hamiltonian and its wave function of one-dimensional gapless hinge states with semi-infinite boundary conditions based on the effective Hamiltonian of two-dimensional surface states. In particular, we find that the hinge states on the two sides of the same surface can couple to produce a finite energy gap.
