Janus VXY monolayers with tunable large Berry curvature  

作　　者：Wenrong Liu Xinyang Li Changwen Zhang Shishen Yan 

机构地区：[1]School of Physics and Technology,Spintronics Institute,University of Jinan,Jinan 250022,China

出　　处：《Journal of Semiconductors》2022年第4期96-111,共16页半导体学报（英文版）

基　　金：supported by the National Natural Science Foundation of China (Grant No. 52173283);Taishan Scholar Program of Shandong Province (No. ts20190939);the Independent Cultivation Program of Innovation Team of Jinan City (Grant No. 2021GXRC043);Science and technology program of the University of Jinan (No. XKY1912)。

摘　　要：The Rashba effect and valley polarization provide a novel paradigm in quantum information technology. However,practical materials are scarce. Here, we found a new class of Janus monolayers VXY(X = Cl, Br, I;Y = Se, Te) with excellent valley polarization effect. In particular, Janus VBrSe shows Zeeman type spin splitting of 14 meV, large Berry curvature of 182.73 bohr2,and, at the same time, a large Rashba parameter of 176.89 meV·?. We use the k·p theory to analyze the relationship between the lattice constant and the curvature of the Berry. The Berry curvature can be adjusted by changing the lattice parameter,which will greatly improve the transverse velocities of carriers and promote the efficiency of the valley Hall device. By applying biaxial strain onto VBrSe, we can see that there is a correlation between Berry curvature and lattice constant, which further validates the above theory. All these results provide tantalizing opportunities for efficient spintronics and valleytronics.

关 键 词：Janus VXY valley polarization k·p theory large Berry curvature 

分 类 号：O469[理学—凝聚态物理]