Lv Qianqian, Fu Pei-Hao, Zhuang Quan, Yu Xiang-Long, Wu Jiansheng
Department of Physics, Harbin Institute of Technology, Harbin 150001, People's Republic of China.
Department of Physics, Southern University of Science and Technology, Shenzhen 518055, People's Republic of China.
J Phys Condens Matter. 2022 Nov 1;34(50). doi: 10.1088/1361-648X/ac9bb9.
Materials with interactions between the topology and magnetism are triggering increasing interest. We constructed a two-dimensional (2D) van der Waals heterostructure germanene/MnS, where the germanene is a quantum spin Hall insulator and MnSprovides antiferromagnetic (AFM) interactions. In this structure, a 2D AFM nodal-line semimetal (NLSM) phase is expected without the spin-orbit coupling (SOC), which is of a high density of states around the Fermi level. The band touching rings originate from the intersection between different spin components oforbitals of germanene. This result provides a possible 2D realization of NLSMs, which are usually realized in three-dimensional systems. When the SOC is present, a quantum anomalous Hall (QAH) state emerges with the annihilation of the band-touching rings. The nontrivial topology is determined by calculating the Chern number and Wannier charge centers. This provides an alternative platform to realize QAH states. These results could also provide the possibility of further understanding the topological states in NLSM and electronic applications.
具有拓扑结构与磁性之间相互作用的材料正引发越来越多的关注。我们构建了一种二维（2D）范德华异质结构锗烯/MnS，其中锗烯是一种量子自旋霍尔绝缘体，而MnS提供反铁磁（AFM）相互作用。在这种结构中，预计在没有自旋轨道耦合（SOC）的情况下会出现二维AFM节线半金属（NLSM）相，其在费米能级附近具有高态密度。能带接触环源自锗烯轨道不同自旋分量之间的交叉。这一结果提供了一种NLSM的二维实现可能性，NLSM通常在三维系统中实现。当存在SOC时，随着能带接触环的湮灭会出现量子反常霍尔（QAH）态。通过计算陈数和万尼尔电荷中心来确定非平凡拓扑结构。这提供了一个实现QAH态的替代平台。这些结果也可能为进一步理解NLSM中的拓扑态和电子应用提供可能性。
