论文标题
在二维方形晶格抗fiferromagnet中光学诱导的拓扑相变
Optically Induced Topological Phase Transition in two dimensional Square Lattice Antiferromagnet
论文作者
论文摘要
最近发现，具有自旋轨道耦合和非肌形成对称性的二维方晶格抗铁磁铁是拓扑绝缘子（TI）。我们从理论上研究了具有光照射的抗铁磁晶体的浮雕状态，这可以适用于光旋转。带有圆极化的光照射可导致拓扑相变为量子异常霍尔（QAH）阶段，而Chern数则不同。在相边界上，浮点系统可以使用一个，两个或三个带谷进行半学。线性极化光场会诱导有效的抗铁磁交换场，从而改变Ti的相位状态。在两个相边界的交点处，散装带结构几乎沿着第一布里渊区的高对称线之一是平坦的，这会导致大块和纳米骨中的费米能量靠近费米能量。
The two dimensional square lattice antiferromagnet with spin-orbit coupling and nonsymmorphic symmetry is recently found to be topological insulator (TI). We theoretically studied the Floquet states of the antiferromagnetic crystal with optical irradiation, which could be applicable in opto-spintronic. An optical irradiation with circular polarization induces topological phase transition into quantum Anomalous Hall (QAH) phase with varying Chern number. At the phase boundaries, the Floquet systems could be semimetal with one, two or three band valleys. A linear polarized optical field induces effective antiferromagnetic exchange field, which change the phase regime of the TI. At the intersection of two phase boundaries, the bulk band structure is nearly flat along one of the high symmetry line in the first Brillouin zone, which result in large density of states near to the Fermi energy in bulk and nanoribbons.
