Plain s-wave superconductivity in single-layer Fe Se on SrTiO3 probed by scanning tunnelling microscopy
Plain s-wave superconductivity in single-layer Fe Se on SrTiO3 probed by scanning tunnelling microscopy
复制标题
用扫描隧道显微镜探测 SrTiO3 上单层 Fe Se 的平面横波超导性
DOI：
10.1038/nphys3450
复制
发表时间：
2015-11-01
期刊：
影响因子：
19.6
通讯作者：
Feng, D. L.
中科院分区：
文献类型：
--
作者：
Fan, Q.;Zhang, W. H.;Feng, D. L.
Single-layer Fe Se film on SrTiO3(001) has recently come to the fore as an interfacial superconducting system, with a transition temperature that is significantly enhanced with respect to bulk Fe Se. The mechanism for this enhancement, and indeed for the superconductivity itself, is therefore of great interest. Although the film has a simple Fermi surface topology, its pairing symmetry is unclear. By using low-temperature scanning tunnelling microscopy, we have systematically investigated the superconductivity of single-layer FeSe/SrTiO3 films, and report a fully gapped tunnelling spectrum and magnetic vortex lattice in the film. Quasi-particle interference patterns reveal scatterings between and within the electron pockets, and put constraints on possible pairing symmetries. By introducing impurity atoms onto the sample, we show that magnetic impurities such as Cr and Mn can locally suppress the superconductivity, but non-magnetic impurities (Zn, Ag and K) do not. Our results indicate that single-layer FeSe/SrTiO3 has a plain s-wave pairing symmetry, with an order parameter that has the same phase on all Fermi surface sections.
