非磁性半金属YBi中极大磁电阻及拓扑电子结构构建

Extreme Magnetoresistance and Topological Electronic Structure Construction in Nonmagnetic Semimetal YBi

通过自助溶剂法制备YBi单晶,并研究其磁输运行为及电子结构.零磁场下, YBi具有金属导电特性.磁场作用下,低温电阻将会极大增强,呈现类似拓扑绝缘体的电阻平台.科勒关系表明YBi中具有多种载流子.第一性原理计算表明,该材料具有一个电子带和两个空穴带,且电子和空穴的数目大致相当.此外,我们还发现YBi具有非平庸的电子能带结构.实验表征及理论计算表明,YBi的极大磁电阻来源于电子-空穴补偿效应及拓扑能带结构.

In this paper, the YBi single crystal is synthesized by the self-flux method to study its magnetotransport behavior and electronic structure. Under the zero magnetic field, this compound shows metallic properties. When the magnetic field is applied, the low-temperature resistivity is significantly enhanced, exhibiting a topological insulator resembling a resistivity plateau. Kohler’ s rule suggests that more than one type of carrier exists in YBi. The experimental measurement and theoretical calculation show that electron-hole compensation and nontrivial electronic structure are responsible for the extremely large magnetoresistance in this titled compound.