TY - JOUR
T1 - Observation of a Dirac nodal line in AlB2
AU - Takane, Daichi
AU - Souma, Seigo
AU - Nakayama, Kosuke
AU - Nakamura, Takechika
AU - Oinuma, Hikaru
AU - Hori, Kentaro
AU - Horiba, Kouji
AU - Kumigashira, Hiroshi
AU - Kimura, Noriaki
AU - Takahashi, Takashi
AU - Sato, Takafumi
N1 - Funding Information:
This work was supported by a Grant-in-Aid for Scientific Research on Innovative Areas “Topological Materials Science” (JSPS KAKENHI No: JP15H05853), Grant-in-Aid for Scientific Research (JSPS KAKENHI No. JP17H01139, No. JP18H01160, and JP18H04472), Grant-in-Aid for JSPS Research Fellow (No. JP18J20058) and KEK-PF (Proposal No. 2018S2-001 and No. 2016G555).
Publisher Copyright:
© 2018 American Physical Society.
PY - 2018/7/17
Y1 - 2018/7/17
N2 - We have performed angle-resolved photoemission spectroscopy of AlB2 which is isostructural to high-temperature superconductor MgB2. Using soft-x-ray photons, we accurately determined the three-dimensional bulk band structure and found a highly anisotropic Dirac-cone band at the K point in the bulk hexagonal Brillouin zone. This band disperses downward on approaching the H point while keeping its degeneracy at the Dirac point, producing a characteristic Dirac nodal line along the KH line. We also found that the band structure of AlB2 is regarded as a heavily electron-doped version of MgB2 and is therefore well suited for fully visualizing the predicted Dirac nodal line. The present results suggest that the (Al,Mg)B2 system is a promising platform for studying the interplay among the Dirac nodal line, carrier doping, and possible topological superconducting properties.
AB - We have performed angle-resolved photoemission spectroscopy of AlB2 which is isostructural to high-temperature superconductor MgB2. Using soft-x-ray photons, we accurately determined the three-dimensional bulk band structure and found a highly anisotropic Dirac-cone band at the K point in the bulk hexagonal Brillouin zone. This band disperses downward on approaching the H point while keeping its degeneracy at the Dirac point, producing a characteristic Dirac nodal line along the KH line. We also found that the band structure of AlB2 is regarded as a heavily electron-doped version of MgB2 and is therefore well suited for fully visualizing the predicted Dirac nodal line. The present results suggest that the (Al,Mg)B2 system is a promising platform for studying the interplay among the Dirac nodal line, carrier doping, and possible topological superconducting properties.
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U2 - 10.1103/PhysRevB.98.041105
DO - 10.1103/PhysRevB.98.041105
M3 - Article
AN - SCOPUS:85050465690
SN - 2469-9950
VL - 98
JO - Physical Review B
JF - Physical Review B
IS - 4
M1 - 041105
ER -