Zhang Wei-Xi, Li Yong, Jin Hui, She Yan-Chao
Department of Physics and Electronic Engineering, Tongren University, Tongren 554300, People's Republic of China.
Phys Chem Chem Phys. 2019 Aug 28;21(32):17740-17745. doi: 10.1039/c9cp03337h. Epub 2019 Aug 1.
Recently, the discovery of two-dimensional transition-metal materials with non-trivial magnetic and electronic properties has spurred huge interest in investigating their applications in nanotechnology. Here, we report that the monolayer of CoBr possesses a quantum anomalous Hall insulating phase generated on the basis of first-principles calculations. We find that the CoBr monolayer is an intrinsic two-dimensional ferromagnetic material with a Curie temperature T = 264 K predicted from Monte Carlo simulations. The phonon spectra analysis indicates that the CoBr monolayer is dynamically stable. Taking into account spin-orbit coupling, this makes the electronic structure of the CoBr monolayer topologically non-trivial with a global band gap of 8.7 meV. The anomalous Hall conductivity calculation shows a Chern number C = 2, meaning the presence of a two edge state in nanoribbons of finite width. These findings not only add an experimentally feasible member to the quantum anomalous Hall insulator family, but also pave the way for highly promising application potentials in nanoelectronics and spintronics.
最近，具有非平凡磁性和电子特性的二维过渡金属材料的发现激发了人们对研究其在纳米技术中应用的巨大兴趣。在此，我们报告基于第一性原理计算，单层CoBr具有量子反常霍尔绝缘相。我们发现CoBr单层是一种本征二维铁磁材料，蒙特卡罗模拟预测其居里温度T = 264 K。声子谱分析表明CoBr单层是动态稳定的。考虑到自旋轨道耦合，这使得CoBr单层的电子结构在拓扑上非平凡，全局带隙为8.7 meV。反常霍尔电导率计算显示陈数C = 2，这意味着在有限宽度的纳米带中存在两个边缘态。这些发现不仅为量子反常霍尔绝缘体家族增添了一个实验上可行的成员，也为纳米电子学和自旋电子学中极具潜力的应用铺平了道路。
