Janus VXY monolayers with tunable large Berry curvature

• 作者: Wenrong Liu Xinyang Li Changwen Zhang Shishen Yan
• 来源期刊: 半导体学报（英文版）
• 年，卷（期）: 2022,（4）
• 所属期刊栏目: ARTICLES
• 页码范围: 101-110
• 页数: 10页
• 语种: 英文
• DOI: 10.1088/1674-4926/43/4/042501

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 val-ley 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 valid-ates the above theory.All these results provide tantalizing opportunities for efficient spintronics and valleytronics.