Prominent metallic surface conduction and the singular magnetic response of topological Dirac fermion in three-dimensional topological insulator Bi_1.5Sb_0.5Te_1.7Se_1.3.

ABSTRACT: We report semiconductor to metal-like crossover in the temperature dependence of resistivity (ρ) due to the switching of charge transport from bulk to surface channel in three-dimensional topological insulator Bi_1.5Sb_0.5Te_1.7Se_1.3. Unlike earlier studies, a much sharper drop in ρ(T) is observed below the crossover temperature due to the dominant surface conduction. Remarkably, the resistivity of the conducting surface channel follows a rarely observable T ² dependence at low temperature, as predicted theoretically for a two-dimensional Fermi liquid system. The field dependence of magnetization shows a cusp-like paramagnetic peak in the susceptibility (χ) at zero field over the diamagnetic background. The peak is found to be robust agai

SUBMITTER: Dutta P 

PROVIDER: S-EPMC5501823 | biostudies-literature | 2017 Jul

REPOSITORIES: biostudies-literature