Identifying s-wave pairing symmetry in single-layer FeSe from topologically trivial edge states

作     者：Wei, Zhongxu Qin, Shengshan Ding, Cui Hu, Jiangping Sun, Yujie Wang, Lili Xue, Qi-Kun 

作者机构：Department of Physics Southern University of Science and Technology Shenzhen518055 China State Key Laboratory of Low-Dimensional Quantum Physics Department of Physics Tsinghua University Beijing10008 China Kavli Institute of Theoretical Sciences University of Chinese Academy of Sciences Beijing100049 China CAS Center for Excellence in Topological Quantum Computation University of Chinese Academy of Sciences Beijing100049 China Beijing Academy of Quantum Information Sciences Beijing100193 China Beijing National Research Center for Condensed Matter Physics Institute of Physics Chinese Academy of Sciences Beijing100190 China 

出 版 物：《arXiv》 (arXiv)

年 卷 期：2022年

核心收录：

主　　题：Iron compounds 

摘      要：Determining the pairing symmetry of single-layer FeSe on SrTiO3 is the key to understanding the enhanced pairing mechanism;furthermore, it guides exploring new superconductors with high transition temperatures (Tc). Despite significant efforts, it remains controversial whether the symmetry is the sign-preserving s- or the sign-changed s±-wave. Here, we investigate the pairing symmetry of single-layer FeSe from a topological point of view. Using low-temperature scanning tunneling microscopy/spectroscopy, we have systematically characterized the superconducting states at isolated edges and corners of single-layer FeSe. The tunneling spectra collected at edges and corners exhibit full gap and substantial dip, respectively, demonstrating the absence of topologically non-trivial edge/corner modes. According to the theoretical calculation, these spectroscopic features are strong evidence for the sign-preserving s-wave pairing. © 2022, CC BY-NC-ND.