Atomic and electronic structure of ultrathin Bi(111) films grown on Bi2Te3(111) substrates: evidence for a strain-induced topological phase transition.
We studied the atomic and electronic structures of ultrathin Bi(111) films grown on Bi(2)Te(3) by means of angle-resolved photoemission, first-principles calculations, and low-energy electron diffraction. These Bi films were found to be strained due to the influence of the substrate. Accordingly, the band structure is affected and Bi undergoes a topological phase transition; it is shown that the Z(2) topological invariant in three dimensions switches from +1 (trivial) to -1 (nontrivial or topological). This was clearly confirmed from the change in the surface-state dispersion near the Fermi level. Our discovery offers a method to produce novel topological systems from simple materials.
Department of Physics, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan. hirahara@surface.phys.s.u-tokyo.ac.jp
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T
Hirahara
N
N
Fukui
T
T
Shirasawa
M
M
Yamada
M
M
Aitani
H
H
Miyazaki
M
M
Matsunami
S
S
Kimura
T
T
Takahashi
S
S
Hasegawa
K
K
Kobayashi