Common (π,π) Band Folding and Surface Reconstruction in FeAs-Based Superconductors

• 作者: Yongqing Cai Tao Xie Huan Yang Dingsong Wu Jianwei Huang Wenshan Hong Lu Cao Chang Liu Cong Li Yu Xu Qiang Gao Taimin Miao Guodong Liu Shiliang Li Li Huang Huiqian Luo Zuyan Xu Hongjun Gao Lin Zhao X.J.Zhou
• 来源期刊: 中国物理快报（英文版）
• 年，卷（期）: 2021,（5）
• 所属期刊栏目: CONDENSED MATTER:ELECTRONIC STRUCTURE,ELECTRICAL,MAGNETIC,AND OPTICAL PROPERTIES
• 页码范围: 138-143
• 页数: 6页
• 语种: 英文
• DOI: 10.1088/0256-307X/38/5/057404

摘要

High resolution angle-resolved photoemission spectroscopy (ARPES) measurements are carried out on CaKFe4As4,KCa2Fe4As4F2 and (Ba0.6K0.4)Fe2As2 superconductors.Clear evidence of band folding between the Brillouin zone center and corners with a (π,π) wave vector has been found from the measured Fermi surface and band structures in all the three kinds of superconductors.A dominant √2 × √2 surface reconstruction is observed on the cleaved surface of CaKFe4As4 by scanning tunneling microscopy (STM) measurements.We propose that the commonly observed √2 × √2 reconstruction in the FeAs-based superconductors provides a general scenario to understand the origin of the (π,π) band folding.Our observations provide new insights in understanding the electronic structure and superconductivity mechanism in iron-based superconductors.