Anisotropic Dirac fermions in a Bi square net of SrMnBi2.
We report the observation of highly anisotropic Dirac fermions in a Bi square net of SrMnBi(2), based on a first-principles calculation, angle-resolved photoemission spectroscopy, and quantum oscillations for high-quality single crystals. We found that the Dirac dispersion is generally induced in the (SrBi)(+) layer containing a double-sized Bi square net. In contrast to the commonly observed isotropic Dirac cone, the Dirac cone in SrMnBi(2) is highly anisotropic with a large momentum-dependent disparity of Fermi velocities of ~8. These findings demonstrate that a Bi square net, a common building block of various layered pnictides, provides a new platform that hosts highly anisotropic Dirac fermions.
Department of Physics, Pohang University of Science and Technology, Pohang 790-784, Korea.
Joonbum
J
Park
G
G
Lee
F
F
Wolff-Fabris
Y Y
YY
Koh
M J
MJ
Eom
Y K
YK
Kim
M A
MA
Farhan
Y J
YJ
Jo
C
C
Kim
J H
JH
Shim
J S
JS
Kim