Condensed Matter Physics, 2017, vol. 20, No. 4, 43701
DOI:10.5488/CMP.20.43701

Title: Integer quantum Hall effect and topological phase transitions in silicene
Author(s):
  Y.L. Liu (Faculty of Electric Information Engineering, Huaiyin Institute of Technology, Huaian 223001, China) ,
  G.X. Luo (Department of Physics, Yancheng Institute of Technology, Jiangsu 224051, China) ,
  N. Xu (Department of Physics, Yancheng Institute of Technology, Jiangsu 224051, China) ,
  H.Y. Tian (School of Physics and Electronic Engineering, Linyi University, Linyi 276005, China) ,
  C.D. Ren (Department of Physics, Zunyi Normal College, Guizhou 563002, China)

We numerically investigate the effects of disorder on the quantum Hall effect (QHE) and the quantum phase transitions in silicene based on a lattice model. It is shown that for a clean sample, silicene exhibits an unconventional QHE near the band center, with plateaus developing at ν=0, ±2, ±6,…, and a conventional QHE near the band edges. In the presence of disorder, the Hall plateaus can be destroyed through the float-up of extended levels toward the band center, in which higher plateaus disappear first. However, the center ν=0 Hall plateau is more sensitive to disorder and disappears at a relatively weak disorder strength. Moreover, the combination of an electric field and the intrinsic spin-orbit interaction (SOI) can lead to quantum phase transitions from a topological insulator to a band insulator at the charge neutrality point (CNP), accompanied by additional quantum Hall conductivity plateaus.

Key words: quantum Hall effect, silicene, quantum phase transitions
PACS: 73.43.-f, 73.43.Nq, 72.80.Ey


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