Bi0.96Sb0.04单晶体的量子振荡及输运性质  

Quantum oscillation and transport properties of Bi0.96Sb0.04 single crystal

作　　者：徐恭勤[1] 柯志坚[1] 陈晓伟 潘宇 毛兴宇[1] XU Gongqin;KE Zhijian;CHEN Xiaowei;PAN Yu;MAO Xingyu(School of Science,Jimei University,Xiamen 361021,China;Van der Waals-Zeeman Institute,University of Amsterdam,Amsterdam 1098XH,Netherland)

机构地区：[1]集美大学理学院,福建厦门361021 [2]阿姆斯特丹大学范德瓦斯-塞曼学院,荷兰阿姆斯特丹1098XH

出　　处：《厦门大学学报（自然科学版）》2019年第5期742-747,共6页Journal of Xiamen University：Natural Science

基　　金：国家自然科学基金青年科学基金(51601068);福建省自然科学基金(2016J05129)

摘　　要：铋锑(Bi1-xSbx)合金在拓扑绝缘体的研究中具有重要的意义,Bi0.96Sb0.04单晶体的体电子具有类似狄拉克锥型的电子结构,具有特别的研究价值.通过对Bi0.96Sb0.04单晶体输运性质的测量发现其电阻率在温度高于120 K呈现出类半导体材料的性质,而在低于120 K呈现出类金属材料的性质.外加磁场后,其输运性质在低温和低场时观察到明显的弱反局域化特点.样品的磁电阻在高场下表现出了舒勃尼科夫-德哈斯(Shubnikov de Hass,SdH)振荡,且这一量子振荡在样品的霍尔电阻上表现得更加清晰,霍尔效应和量子振荡实验数据推算的载流子迁移率相互吻合.通过旋转被测样品在磁场中的角度,可以推测出输运过程主要由体电子承担,并得到费米面的大致形状近似为长短轴之比约为1.36∶1的椭球面.The Bi1-xSbx alloy bears special significance in topological insulator research.This paper reports transport properties of Bi0.96Sb0.04 alloy.Here we focus on Bi0.96Sb0.04 single crystal in which the conduction band and the valence band are joined,displaying the Dirac electronic structure.Measurements of it s transport characteristics show that,in terms of the resistance,Bi0.96Sb0.04 alloy behaves like the semiconductor below 120 K and like the metallic above 120 K.In very low temperatures under weak magnetic fields,the resistance shows weak anti-localization(WAL)characters.Under high magnetic fields,the Shubnikov de Haas(SdH)oscillation in magneto-resistance is observed,and even better shaped SdH-like oscillation in its Hall resistance is observed.Further analyses show that the quantum oscillation in transport measurements originates from bulk electrons.By analyzing the detail of SdH oscillations along with the rotating of the sample in the magnetic field,we perceive a rough picture of its Fermi surface which is an ellipsoid with a ratio of approximately 1.36∶1.

关 键 词：狄拉克半金属 铋锑合金 量子振荡 输运性质 

分 类 号：O469[理学—凝聚态物理]