论文标题
磁性拓扑绝缘子的费米表面上的动量内向对称性破裂
Momentum-inversion symmetry breaking on the Fermi surface of magnetic topological insulators
论文作者
论文摘要
磁性拓扑绝缘子（MNBI $ _2 $ te $ _4 $）（bi $ _2 $ _2 $ te $ _3 $）$ _ n $被预计会表现出磁能差距，而最近的光谱研究并未观察到它们。因此，表面上的磁性正在争论中。在这项工作中，我们提出了另一个对称标准来探测表面磁性。由于时间反转的对称性对称性和反转对称性的破坏，我们证明了表面带结构违反了动量内向对称性，并且导致Fermi表面上表面状态在Fermi表面上的三倍而不是六倍的旋转对称性，如果表面状态非常与表面磁性相对应。这种动量内向对称性违规在（0001）平面上的表面频段的$γ-k $方向上是显着的。
Magnetic topological insulators (MnBi$_2$Te$_4$)(Bi$_2$Te$_3$)$_n$ were anticipated to exhibit magnetic energy gaps while recent spectroscopic studies did not observe them. Thus, magnetism on the surface is under debate. In this work, we propose another symmetry criterion to probe the surface magnetism. Because of both time-reversal symmetry-breaking and inversion symmetry-breaking, we demonstrate that the surface band structure violates momentum-inversion symmetry and leads to a three-fold rather than six-fold rotational symmetry on the Fermi surface if corresponding surface states couple strongly to the surface magnetism. Such a momentum-inversion symmetry violation is significant along the $Γ-K$ direction for surface bands on the (0001) plane.
