Landau quantization and the thickness limit of topological insulator thin films of Sb2Te3.
We report the experimental observation of Landau quantization of molecular beam epitaxy grown Sb{2}Te{3} thin films by a low-temperature scanning tunneling microscope. Different from all the reported systems, the Landau quantization in a Sb{2}Te{3} topological insulator is not sensitive to the intrinsic substitutional defects in the films. As a result, a nearly perfect linear energy dispersion of surface states as a 2D massless Dirac fermion system is achieved. We demonstrate that four quintuple layers are the thickness limit for a Sb{2}Te{3} thin film being a 3D topological insulator. The mechanism of the Landau-level broadening is discussed in terms of enhanced quasiparticle lifetime.
Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China.
Yeping
Y
Jiang
Yilin
Y
Wang
Mu
M
Chen
Zhi
Z
Li
Canli
C
Song
Ke
K
He
Lili
L
Wang
Xi
X
Chen
Xucun
X
Ma
Qi-Kun
QK
Xue