Te元素掺杂Bi_2Se_3拓扑绝缘体纳米线的反弱局域效应（英文）  

Weak antilocalization effect in Tellurium-doped Bi_2Se_3 topological insulator nanowires

作　　者：田锋[1,2] 周远明[1,2] 张小强[3] 魏来明[3] 梅菲[1,2] 徐进霞[1,2] 蒋妍[1,2] 吴麟章[2] 康亭亭[4] 俞国林[4] 

机构地区：[1]湖北工业大学太阳能高效利用湖北省协同创新中心,湖北武汉430068 [2]湖北工业大学电气与电子工程学院,湖北武汉430068 [3]中国科学技术大学合肥微尺度物质科学国家实验室,安徽合肥230026 [4]中国科学院上海技术物理研究所红外物理国家重点实验室,上海200083

出　　处：《红外与毫米波学报》2017年第3期270-275,共6页Journal of Infrared and Millimeter Waves

基　　金：Supported by the National Natural Science Foundation of China(11304092,51371079,11305056,11304299,51602099);the Open Foundation of Hubei Collaborative Innovation Center for High-efficiency Utilization of Solar Energy(HBSKFZD2014001,HBSKFM2014006,HBSKFM2014013,HBSKFM2014015)

摘　　要：采用Au催化的固-液-气(VLS)方法制备了单晶Bi_2Se_3和Bi_2(Te_xSe_(1-x))_3纳米线,研究了单根纳米线器件的输运性质.在对单根Bi_2(Te_xSe_(1-x))3(x=0.26)纳米线的低温磁输运测试中观察到反弱局域效应,说明样品中存在较强的自旋-轨道耦合.结果表明,Te掺杂可以有效抑制体电导对输运过程的影响.通过对不同温度下的磁电导曲线进行拟合,得到了电子的退相干长度l_φ,l_φ从1.5 K时的389 nm减小至20 K时的39 nm,遵循l_φ∝T^(-0.96)指数变化规律.分析表明,在Te掺杂样品的输运过程中,电子-电子散射和电子-声子散射均起到了十分重要的作用.Single-crystalline Bi2Se3 and Bi2 （TexSel_x ）z nanowires were synthesized via Au catalytic vapor-liquid- solid （VLS） growth method. Electronic properties of the surface states in individual Bi2 （TexSel_x ）3 （x = 0.26） nanowire were studied by low-temperature magnetotransport measurement. Weak antilocalization （WAL） effect was found, suggesting strong spin-orbit coupling in our samples. It is indicated that the bulk effect can be sup- pressed effectively by the Tellurium （Te） doping. By fitting the magnetoconductance curves at magnetic field up to 7 T measured at different temperatures, the extracted dephasing length / decreases from 389 nm at 1.5 K to 39 nm at 20 K, which can be well described by the power law l_φ∝T^（-0.96）. It can be reasonably deduced that both the elec- tron-electron scattering and the electron-phonon scattering play important roles in the Te-doped sample.

关 键 词：拓扑绝缘体 Bi2Se3纳米线 反弱局域 退相干长度 

分 类 号：O413.1[理学—理论物理]