论文标题
域墙壁装修的反铁磁拓扑绝缘子MNBI $ _ {2n} $ te $ _ {3n+1} $的拓扑表面
Topological surfaces of domain wall-decorated antiferromagnetic topological insulator MnBi$_{2n}$Te$_{3n+1}$
论文作者
论文摘要
抗磁性拓扑绝缘子具有受反独立$ s $对称性保护的拓扑内间隙状态，该状态因不可避免的域壁而破坏。在其拓扑表面上，带有域壁的抗铁磁拓扑绝缘子是否具有无间隙和金属，尚待阐明。我们表明，一个非统计指数表征了域壁装饰的抗磁性拓扑绝缘子的磁性，称为ISING时刻，确定了拓扑表面间隙，即使$ S $对称性也可能是零的，即使显然是损坏了$ s $的对称性。在热力学极限中，当磁性波动界定时，拓扑表面状态往往是无间隙的。在这种情况下，由于从正交到手性正交对称类别的交叉，表面转移矩阵的Lyapunov指数在零能量附近揭示了表面离域转变。表面状态上的光谱和传输测量将揭示过渡的临界行为，而反磁性结构域壁的性质具有回报。
Antiferromagnetic topological insulators harbor topological in-gap surface states protected by an anti-unitary $S$ symmetry, which is broken by the inevitable presence of domain walls. Whether an antiferromagnetic topological insulator with domain walls is gapless and metallic on its topological surfaces remains to be elucidated. We show that a single non-statistical index characterizing the magnetic order of domain wall-decorated antiferromagnetic topological insulator, referred to as the Ising moment, determines the topological surface gap, which can be zero even when the $S$ symmetry is manifestly broken. In the thermodynamic limit, the topological surface states tend to be gapless when magnetic fluctuation is bounded. In this case, the Lyapunov exponent of the surface transfer matrix reveals a surface delocalization transition near the zero energy due to a crossover from orthogonal to chiral orthogonal symmetry class. Spectroscopic and transport measurements on the surface states will reveal the critical behavior of the transition, which in return bears on the nature of antiferromagnetic domains walls.
