Dynamic conductivity of the bulk states of n-type HgTe/CdTe quantum well topological insulator

Authors

Qinjun Chen, University of WollongongFollow
Matthew Sanderson, University of WollongongFollow
J C. Cao, Shanghai Institute of Microsystem and Information Technology
Chao Zhang, University of WollongongFollow

RIS ID

95917

Publication Details

Chen, Q., Sanderson, M., Cao, J. C. & Zhang, C. (2014). Dynamic conductivity of the bulk states of n-type HgTe/CdTe quantum well topological insulator. Applied Physics Letters, 105 202110-1-202110-5.

Abstract

We theoretically studied the frequency-dependent current response of the bulk state of topological insulator HgTe/CdTe quantum well. The optical conductivity is mainly due to the inter-band process at high frequencies. At low frequencies, intra-band process dominates with a dramatic drop to near zero before the inter-band contribution takes over. The conductivity decreases with temperature at low temperature and increases with temperature at high temperature. The transport scattering rate has an opposite frequency dependence in the low and high temperature regime. The different frequency dependence is due to the interplay of the carrier-impurity scattering and carrier population near the Fermi surface.