论文标题
拓扑绝缘子中的磁性翘曲
Magnetic warping in topological insulators
论文作者
论文摘要
我们分析了磁性绝缘子家族中拓扑表面状态的电子结构mnbi $ _ {2n} $ te $ _ {3n+1} $。我们表明，在自然切换表面，狄拉克锥翘曲在磁性秩序温度下从六角形变为三角形。特别是，在形成远距离磁性阶时，能量分裂会在同一带指数的表面状态之间发展，但表面动量相反。因此，这种能量分割的测量构成了一种简单的协议，可以通过表面电子结构检测磁性排序，替代检测表面磁性间隙。有趣的是，尽管后者标志着非零的表面磁通量，但此处预测的三角形翘曲还对表面磁通的方向敏感。
We analyze the electronic structure of topological surface states in the family of magnetic topological insulators MnBi$_{2n}$Te$_{3n+1}$. We show that, at natural-cleavage surfaces, the Dirac cone warping changes its symmetry from hexagonal to trigonal at the magnetic ordering temperature. In particular, an energy splitting develops between the surface states of same band index but opposite surface momenta upon formation of the long-range magnetic order. As a consequence, measurements of such energy splittings constitute a simple protocol to detect the magnetic ordering via the surface electronic structure, alternative to the detection of the surface magnetic gap. Interestingly, while the latter signals a nonzero surface magnetic flux, the trigonal warping predicted here is, in addition, sensitive to the direction of the surface magnetic flux.
