期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2020
卷号：117
期号：1
页码：221-227
DOI：10.1073/pnas.1914534117
出版社：The National Academy of Sciences of the United States of America
摘要：The recent discovery of the interfacial superconductivity (SC) of the Bi2 Te3 /Fe1+y Te heterostructure has attracted extensive studies due to its potential as a novel platform for trapping and controlling Majorana fermions. Here we present studies of another topological insulator (TI)/Fe1+y Te heterostructure, Sb2 Te3 /Fe1+y Te, which also has an interfacial 2-dimensional SC. The results of transport measurements support that reduction of the excess Fe concentration of the Fe1+y Te layer not only increases the fluctuation of its antiferromagnetic (AFM) order but also enhances the quality of the SC of this heterostructure system. On the other hand, the interfacial SC of this heterostructure was found to have a wider-ranging TI-layer thickness dependence than that of the Bi2 Te3 /Fe1+y Te heterostructure, which is believed to be attributed to the much higher bulk conductivity of Sb2 Te3 that enhances indirect coupling between its top and bottom topological surface states (TSSs). Our results provide evidence of the interplay among the AFM order, itinerant carries from the TSSs, and the induced interfacial SC of the TI/Fe1+y Te heterostructure system.
关键词：iron-based parent compound ; topological insulator ; interfacial superconductivity ; spin fluctuation of antiferromagnetic order ; itinerant carriers of topological surface states
