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Title: Photoconductivity oscillations in surface state of three-dimensional topological insulator subjected to a magnetic field

We describe a theoretical study of the terahertz (THz) radiation field-induced dc transport response of the surface state of a 3D topological insulator that has been subjected to a perpendicular magnetic field. Using the Landau–Floquet state and linear response theory, we obtain the photoconductivity characteristics for various types of polarized THz field. The longitudinal photoconductivity shows a clear oscillatory dependence on ω/ω{sub B}, where ω{sub B}=v{sub F}√(2eB/ℏ). This oscillation occurs because of the oscillatory structure of the Landau density of states and occurs in agreement with the photon-assisted transitions between the different Landau levels. The THz field's polarization has a major influence on the photoconductivity. A linear transverse polarization will lead to the most obvious oscillation, while the circular polarization is next to it, but the longitudinal polarization has no influence. We also discuss the broadening effect on the impurity potential and its influence. The findings with regard to the interactions between topological insulators and THz fields actually open a path toward the development of THz device applications of topological insulators.
Authors:
; ;  [1]
  1. State Key Laboratory of Optoelectronic Materials and Technologies, Nanotechnology Research Center, School of Materials and Engineering, School of Physics and Engineering, Sun Yat-sen University, Guangzhou 510275, Guangdong (China)
Publication Date:
OSTI Identifier:
22410220
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 117; Journal Issue: 19; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; DENSITY OF STATES; DIRECT CURRENT; FLOQUET FUNCTION; MAGNETIC FIELDS; OSCILLATIONS; PHOTOCONDUCTIVITY; POLARIZATION; SURFACES; THREE-DIMENSIONAL LATTICES; TOPOLOGY