2024-03-28T14:09:41Z
https://nagoya.repo.nii.ac.jp/oai
oai:nagoya.repo.nii.ac.jp:02001515
2023-01-16T05:15:58Z
320:321:322
Ambient-pressure Dirac electron system in the quasi-two-dimensional molecular conductor α−(BETS)2I3
Kitou, Shunsuke
Tsumuraya, Takao
Sawahata, Hikaru
Ishii, Fumiyuki
Hiraki, Ko-ichi
Nakamura, Toshikazu
Katayama, Naoyuki
Sawa, Hiroshi
open access
© 2021 American Physical Society
We investigated the precise crystal structures and electronic states of a quasi-two-dimensional molecular conductor α−(BETS)2I3 at ambient pressure. The electronic resistivity of this molecular solid shows metal-to-insulator (MI) crossover behavior at TMI=50K. Our x-ray diffraction and 13C nuclear magnetic resonance experiments revealed that α−(BETS)2I3 maintains the inversion symmetry below TMI. First-principles calculations found a pair of anisotropic Dirac cones at a general k point, with the degenerate contact points at the Fermi level. The origin of the insulating state in this system is a small energy gap of ∼2meV opened by the spin-orbit interaction. The Z2 topological invariants indicate that this system is a weak topological insulator. Our results suggest that α−(BETS)2I3 is a promising material for studying the bulk Dirac electron system in two dimensions.
American Physical Society
2021-01-15
eng
journal article
VoR
http://hdl.handle.net/2237/0002001515
https://nagoya.repo.nii.ac.jp/records/2001515
https://doi.org/10.1103/PhysRevB.103.035135
2469-9950
Physical Review B
103
035135
https://nagoya.repo.nii.ac.jp/record/2001515/files/PhysRevB_103_035135.pdf
application/pdf
1.6 MB
2021-10-15