Low-velocity anisotropic Dirac fermions on the side surface of topological insulators

Chang Youn Moon, Jinhee Han, Hyungjun Lee, Hyoung Joon Choi

Research output: Contribution to journalArticle

36 Citations (Scopus)

Abstract

We report anisotropic Dirac-cone surface bands on a side-surface geometry of the topological insulator Bi2Se3 revealed by first-principles density-functional calculations. We find that the electron velocity in the side-surface Dirac cone is anisotropically reduced from that in the (111)-surface Dirac cone, and the velocity is not in parallel with the wave vector k except for k in high-symmetry directions. The size of the electron spin depends on the direction of k due to anisotropic variation of the noncollinearity of the electron state. The anisotropy of electronic structures follows the corresponding anisotropy of the surface atomic structure. Low-energy effective Hamiltonian is proposed for side-surface Dirac fermions, and its implications are presented including refractive transport phenomena occurring at the edges of topological insulators where different surfaces meet.

Original languageEnglish
Article number195425
JournalPhysical Review B - Condensed Matter and Materials Physics
Volume84
Issue number19
DOIs
Publication statusPublished - 2011 Nov 7

Fingerprint

Fermions
low speed
fermions
insulators
cones
Cones
Anisotropy
anisotropy
surface geometry
Hamiltonians
electron states
Electrons
atomic structure
electron spin
Electron energy levels
Electronic structure
Density functional theory
electronic structure
symmetry
Geometry

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

Cite this

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Low-velocity anisotropic Dirac fermions on the side surface of topological insulators. / Moon, Chang Youn; Han, Jinhee; Lee, Hyungjun; Choi, Hyoung Joon.

In: Physical Review B - Condensed Matter and Materials Physics, Vol. 84, No. 19, 195425, 07.11.2011.

Research output: Contribution to journalArticle

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