TY - JOUR
T1 - Dirac semimetal phase and switching of band inversion in XMg2Bi2 (X = Ba and Sr)
AU - Takane, Daichi
AU - Kubota, Yuya
AU - Nakayama, Kosuke
AU - Kawakami, Tappei
AU - Yamauchi, Kunihiko
AU - Souma, Seigo
AU - Kato, Takemi
AU - Sugawara, Katsuaki
AU - Ideta, Shin ichiro
AU - Tanaka, Kiyohisa
AU - Kitamura, Miho
AU - Horiba, Koji
AU - Kumigashira, Hiroshi
AU - Oguchi, Tamio
AU - Takahashi, Takashi
AU - Segawa, Kouji
AU - Sato, Takafumi
N1 - Funding Information:
We thank Y. Saruta, T. Taguchi, N. Watanabe, and R. Tsubono for their assistance in the ARPES experiments. We thank K. Nagata for his assistance in the preparation of experiments. This work was supported by JST-CREST (No: JPMJCR18T1), JST-PRESTO (No: JPMJPR18L7), MEXT of Japan (Innovative Area “Topological Materials Science” JP15H05853), JSPS (JSPS KAKENHI No: JP17H01139, JP18H01160, JP19H01845, JP20H01847), Grant-in-Aid for JSPS Research Fellow (No: JP18J20058), KEK-PF (Proposal number: 2018S2-001, 2021S2-001), and UVSOR (Proposal number: 19-555, 19-841, 20-755). D.T. thanks JSPS and Tohoku University Division for Interdisciplinary Advanced Research and Education, T. Kawakami and T. Kato thank GP-Spin, for financial support.
Publisher Copyright:
© 2021, The Author(s).
PY - 2021/12
Y1 - 2021/12
N2 - Topological Dirac semimetals (TDSs) offer an excellent opportunity to realize outstanding physical properties distinct from those of topological insulators. Since TDSs verified so far have their own problems such as high reactivity in the atmosphere and difficulty in controlling topological phases via chemical substitution, it is highly desirable to find a new material platform of TDSs. By angle-resolved photoemission spectroscopy combined with first-principles band-structure calculations, we show that ternary compound BaMg2Bi2 is a TDS with a simple Dirac-band crossing around the Brillouin-zone center protected by the C3 symmetry of crystal. We also found that isostructural SrMg2Bi2 is an ordinary insulator characterized by the absence of band inversion due to the reduction of spin–orbit coupling. Thus, XMg2Bi2 (X = Sr, Ba, etc.) serves as a useful platform to study the interplay among crystal symmetry, spin–orbit coupling, and topological phase transition around the TDS phase.
AB - Topological Dirac semimetals (TDSs) offer an excellent opportunity to realize outstanding physical properties distinct from those of topological insulators. Since TDSs verified so far have their own problems such as high reactivity in the atmosphere and difficulty in controlling topological phases via chemical substitution, it is highly desirable to find a new material platform of TDSs. By angle-resolved photoemission spectroscopy combined with first-principles band-structure calculations, we show that ternary compound BaMg2Bi2 is a TDS with a simple Dirac-band crossing around the Brillouin-zone center protected by the C3 symmetry of crystal. We also found that isostructural SrMg2Bi2 is an ordinary insulator characterized by the absence of band inversion due to the reduction of spin–orbit coupling. Thus, XMg2Bi2 (X = Sr, Ba, etc.) serves as a useful platform to study the interplay among crystal symmetry, spin–orbit coupling, and topological phase transition around the TDS phase.
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U2 - 10.1038/s41598-021-01333-z
DO - 10.1038/s41598-021-01333-z
M3 - Article
C2 - 34754019
AN - SCOPUS:85118672482
SN - 2045-2322
VL - 11
JO - Scientific Reports
JF - Scientific Reports
IS - 1
M1 - 21937
ER -