Zhong Liangshuai, Chen Xiaofang, Qi Jingshan
School of Physics and Electronic Engineering, Jiangsu Normal University, Xuzhou 221116, People's Republic of China.
Phys Chem Chem Phys. 2017 Jun 14;19(23):15388-15393. doi: 10.1039/c7cp00964j.
Monolayer manganese chalcogenophosphates MnPSe possess a pair of non-degenerate energy valleys in the vicinities of the vertices of the hexagonal Brillouin zone, which exhibit fascinating optical valley polarization. However, the spin is still degenerate due to antiferromagnetic coupling between Mn ions. In this paper we propose a strategy to realize simultaneously the spin and valley degeneracy splitting by the doping-induced Zeeman effect in monolayer MnPSe. Using first-principles calculations we demonstrate that in Zn-doped monolayer MnPSe a valley splitting of larger than 20 meV and a spin splitting of larger than 100 meV can be achieved simultaneously. The doping-induced spin and valley splitting is attractive for spintronics and valleytronics as it creates differences in various energy scales between valleys and between spins, which will facilitate the access and manipulation of the valley and spin degrees of freedom by electrical gating in addition to optical pumping.
单层硫族磷化物锰（MnPSe）在六角形布里渊区顶点附近有一对非简并的能量谷，呈现出迷人的光学谷极化现象。然而，由于锰离子之间的反铁磁耦合，自旋仍然是简并的。在本文中，我们提出了一种策略，通过单层MnPSe中的掺杂诱导塞曼效应同时实现自旋和谷简并分裂。使用第一性原理计算，我们证明在锌掺杂的单层MnPSe中，可以同时实现大于20毫电子伏特的谷分裂和大于100毫电子伏特的自旋分裂。掺杂诱导的自旋和谷分裂对自旋电子学和谷电子学具有吸引力，因为它在谷与谷之间以及自旋与自旋之间的各种能量尺度上产生差异，这除了光泵浦之外，还将便于通过电门控来访问和操纵谷和自旋自由度。
