压力诱导的拓扑绝缘体化合物Bi_2Te_3常压相的超导性  

RESSURE-INDUCED SUPERCONDUCTIVITY IN AMBIENT PHASE OF TOPOLOGICAL COMPOUND Bi_2Te_3

作　　者：张俊良[1,2] 张思佳[2] 翁红明[2] 于晓辉[1,2] 张巍[2] 杨留响[2] 刘清青[2] 冯少敏[2] 望贤成[2] 禹日成[2] 曹烈兆[1] 张首晟[3,4] 戴希[2] 方忠[2] 靳常青[2] 

机构地区：[1]中国科学技术大学物理系,合肥230026 [2]中国科学院物理研究所,北京100190 [3]Department of Physics,MeCullough Building,Stanford University,Stanford,CA 94305-4045 [4]清华大学高等研究中心,北京100084

出　　处：《低温物理学报》2012年第1期1-7,共7页Low Temperature Physical Letters

基　　金：国家自然科学基金(批准号:10820101049);科技部国家重点基础研究发展计划(批准号:2007CB925000和2010CB923000)资助的课题~~

摘　　要：通过高压电阻测量,发现了拓扑绝缘体化合物Bi2Te3压力诱导的超导性,在3～6GPa的压力范围内,超导临界温度Tc约为3K.高压下原位同步辐射的结果证明这个超导相来源于常压相结构.通过霍尔效应的测量,发现超导的Bi2Te3样品的载流子为p型.对高压同步辐射结果 Reitveld精修得到的晶格参数和原子位置,并以此进行第一性原理计算,得到的高压下的电子结构仍然保持其拓扑不平凡性.由于Bi2Te3的体超导态和Dirac型的表面态之间的近邻效应,可以出现拓扑超导性.文章也讨论了其体态为拓扑超导体的可能性.pressure-induced superconductivity was observed in a topological compound Bi2 Te3 with Tc of - 3K between 3 to 6 GPa via in-situ high-pressure resistance measurements. The combined in-situ high-pressure structure investigations with synchrotron radiation indicated that the superconductivity occurred with ambient structure before a structure phase transition occurred, p-type carrier was detected in superconducting Bi2 Te3 single crystal by the Hall effects measurements. Consequently, the first-principles calculations based on the structural data obtained by the Rietveld refinement of X-ray diffraction patterns at high pressure showed that the electronic structure under pressure remained topologically nontrivial. The results suggested that topological superconductivity can be realized in Bi2 Te3 due to the proximity effect between superconducting bulk states and Dirac-type surface states. We also discuss the possibility that the bulk state could be a topological superconductor.

关 键 词：拓扑绝缘体 高压 超导性 BI2TE3 

分 类 号：O511[理学—低温物理]