CNR ExploRA

Articolo in rivista, 2021, ENG, 10.1063/5.0045466

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

Liu, D. F.; Wei, L. Y.; Le, C. C.; Wang, H. Y.; Zhang, X.; Kumar, N.; Shekhar, C.; Schroter, N. B. M.; Li, Y. W.; Pei, D.; Xu, L. X.; Dudin, P.; Kim, T. K.; Cacho, C.; Fujii, J.; Vobornik, I.; Wang, M. X.; Yang, L. X.; Liu, Z. K.; Guo, Y. F.; Hu, J. P.; Felser, C.; Parkin, S. S. P.; Chen, Y. L.

Max Planck Inst Microstruct Phys; ShanghaiTech Univ; Max Planck Inst Chem Phys Solids; Univ Oxford; Diamond Light Source; TASC Lab Area Sci Pk; ShanghaiTech Lab Topol Phys; Tsinghua Univ; Frontier Sci Ctr Quantum Informat; Chinese Acad Sci

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 similar to 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 of applied physics 129 (23)