Observation of the critical state to multiple-type Dirac semimetal phases in KMgBi

DOI: 10.1063/5.0045466

Authors: D. F. Liu (Max Planck Institute of Microstructure Physics) , L. Y. Wei (ShanghaiTech University) , C. C. Le (Max Planck Institute for Chemical Physics of Solids) , H. Y. Wang (ShanghaiTech University) , X. Zhang (ShanghaiTech University) , N. Kumar (Max Planck Institute for Chemical Physics of Solids) , C. Shekhar (Max Planck Institute for Chemical Physics of Solids) , N. B. M. Schröter (University of Oxford) , Y. W. Li (ShanghaiTech University) , D. Pei (University of Oxford) , L. X. Xu (ShanghaiTech University) , P. Dudin (Diamond Light Source) , T. K. Kim (Diamond Light Source) , C. Cacho (Diamond Light Source) , J. Fujii (CNR-IOM) , I. Vobornik (CNR-IOM) , M. X. Wang (ShanghaiTech University; ShanghaiTech Laboratory for Topological Physics) , L. X. Yang (Tsinghua University; Frontier Science Center for Quantum Information) , Z. K. Liu (ShanghaiTech University; ShanghaiTech Laboratory for Topological Physics) , Y. F. Guo (ShanghaiTech University) , J. P. Hu (Institute of Physics, Chinese Academy of Sciences) , C. Felser (Max Planck Institute for Chemical Physics of Solids) , S. S. P. Parkin (Max Planck Institute of Microstructure Physics) , Y. L. Chen (ShanghaiTech University; University of Oxford; ShanghaiTech Laboratory for Topological Physics; Tsinghua University)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Journal Of Applied Physics , VOL 129

State: Published (Approved)
Published: June 2021
Diamond Proposal Number(s): 18005

Abstract: Dirac semimetals are classified into different phases based on the types of Dirac fermions. Tuning the transition among different types of Dirac fermions in one system remains a challenge. Recently, KMgBi was predicted to be located at a critical state in which various types of Dirac fermions can be induced owing to the existence of a flatband. Here, we carried out systematic studies on the electronic structure of KMgBi single crystals by combining angle-resolve photoemission spectroscopy and scanning tunneling microscopy/spectroscopy. The flatband was clearly observed near the Fermi level. We also revealed a small bandgap of ∼20 meV between the flatband and the conduction band. These results demonstrate the critical states of KMgBi that transition among various types of Dirac fermions can be tuned in one system.

Journal Keywords: Semimetals; Scanning tunneling microscopy; Dirac fermions; Angle-resolved photoemission spectroscopy; Electronic band structure

Subject Areas: Materials, Physics


Instruments: I05-ARPES

Added On: 22/06/2021 09:25

Documents:
5.0045466.pdf

Discipline Tags:

Quantum Materials Hard condensed matter - electronic properties Physics Materials Science

Technical Tags:

Spectroscopy Angle Resolved Photoemission Spectroscopy (ARPES)