%0 Journal Article
%T Interface-induced superconductivity and strain-dependent spin density wave in FeSe/SrTiO3 thin films
%A S. Y. Tan
%A M. Xia
%A Y. Zhang
%A Z. R. Ye
%A F. Chen
%A X. Xie
%A R. Peng
%A D. F. Xu
%A Q. Fan
%A H. C. Xu
%A J. Juan
%A T. Zhang
%A X. C. Lai
%A T. Xiang
%A J. P. Hu
%A B. P. Xie
%A D. L. Feng
%J Physics
%D 2013
%I arXiv
%R 10.1038/nmat3654
%X The record of superconducting transition temperature(Tc) has long been 56K for the iron-based high temperature superconductors(Fe-HTS's). Recently, in single layer FeSe films grown on SrTiO3 substrate, signs for a new 65K Tc record are reported. Here with in-situ photoemission measurements, we substantiate the presence of the spin density wave(SDW) in FeSe films, a key ingredient of Fe-HTS that was missed in FeSe before, which weakens with increased thickness or reduced strain. We demonstrate that the superconductivity occurs when the electrons transferred from the oxygen-vacant substrate suppress the otherwise most pronounced SDW in single layer FeSe. Besides providing a comprehensive understanding of FeSe films and directions to further enhance its Tc, we establish the phase diagram of FeSe vs. lattice constant that contains all the essential physics of Fe-HTS's. With the simplest structure, cleanest composition and single tuning parameter, it is ideal for testing theories of Fe-HTS's.
%U http://arxiv.org/abs/1301.2748v1