Electronic structure and spatial inhomogeneity of iron-based superconductor FeS

• 来源期刊: 中国物理B（英文版）
• 关键词: angle-resolved photoemission with spatially resolution scanning tunneling microscopy iron-based superconductor electronic band structure
• 年，卷（期）: 2020,（4）
• 页码范围: 123-129
• 页数: 7页
• 语种: 英文
• DOI: 10.1088/1674-1056/ab75d4

摘要

Iron-based superconductor family FeX (X =S, Se, Te) has been one of the research foci in physics and material science due to their record-breaking superconducting temperature (FeSe film) and rich physical phenomena. Recently, FeS, the least studied FeX compound (due to the difficulty in synthesizing high quality macroscopic crystals) attracted much attention because of its puzzling superconducting pairing symmetry. In this work, combining scanning tunneling microscopy and angle resolved photoemission spectroscopy (ARPES) with sub-micron spatial resolution, we investigate the intrinsic electronic structures of superconducting FeS from individual single crystalline domains. Unlike FeTe or FeSe, FeS remains identical tetragonal structure from room temperature down to 5 K, and the band structures observed can be well rceoperxoiduced by our ab-initio calculations. Remarkably, mixed with the 1 × 1 tetragonal metallic phase, we also observe thestence of√5 ×√5 reconstructed insulating phase in the crystal, which not only helps explain the unusual properties of FeS, but also demonstrates the importance of using spatially resolved experimental tools in the study of this compound.