钒基尖晶石AV_(2)O_(4)(A=Mg,Cd,Zn)拓扑平带的理论研究

heoretical Study on Vanadium-based Spinel AV_(2)O_(4)(A=Mg,Cd,Zn)Topological Flat Bands

基于密度泛函理论,运用Materials studio软件的CASTEP模块对3种钒基尖晶石AV_(2)O_(4)(A=Mg,Cd,Zn)进行了第一性原理计算.通过比较3种钒基尖晶石铁磁(FM)构型和反铁磁(AFM)构型的能量,得出反铁磁构型更加稳定的结论.考虑到铁磁态的3种钒基尖晶石平带结构能产生大的反常霍尔效应,分析了铁磁构型下3种钒基尖晶石的电子结构和磁学性质.3种钒基尖晶石在铁磁构型下都保持良好的半金属性,这使其在自旋电子学方面有广泛的应用.此外,分析了三者在费米能级附近的平带性质.在A^(2+)离子的位置掺杂Li~+离子,实现了稳定铁磁态的目的.

Based on the density functional theory,the first-principles calculations for three vanadium-based spinel AV_2O_4(A=Mg,Cd,Zn)were carried out by using the CASTEP module of Materials studio software.By comparing the energies of the three vanadium-based spinel ferromagnetic(FM)configurations and antiferromagnetic(AFM)configurations,it was concluded that the antiferromagnetic configurations were more stable.Considering that the flat band structure of the three vanadium-based spinels in the ferromagnetic state can produce a large anomalous Hall effect,the electronic structure and magnetic properties of the three vanadium-based spinels in the ferromagnetic configuration were analyzed.All three vanadium-based spinels maintain good semimetallic properties in ferromagnetic configurations,which makes them widely used in spintronics.In addition,the flat band properties of the three near the Fermi level are analyzed.Li^(+)is doped at the site of the A^(2+)ion to achieve the stable ferromagnetic state.