Prominent metallic surface conduction and the singular magnetic response of topological Dirac fermion in three-dimensional topological insulator Bi${}_{1.5}$Sb${}_{0.5}$Te${}_{1.7}$Se${}_{1.3}$

Abstract

We report semiconductor to metal-like crossover in temperature dependence of resistivity ($\rho$) due to the switching of charge transport from bulk to surface channel in three-dimensional topological insulator Bi${}_{1.5}$Sb${}_{0.5}$Te${}_{1.7}$Se${}_{1.3}$. Unlike earlier studies, a much sharper drop in $\rho$($T$) 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 ($\chi$) at zero field over the diamagnetic background. The peak is found to be robust against temperature and decays linearly with field from its zero-field value. This unique behavior of $\chi$ is associated with the spin-momentum locked topological surface state of Bi${}_{1.5}$Sb${}_{0.5}$Te${}_{1.7}$Se${}_{1.3}$. The reconstruction of surface state with time is clearly reflected through the reduction of peak height with the age of the sample.

References in corpus (12)

• Discovery (theoretical prediction and experimental observation) of a large-gap topological-insulator class with spin-polarized single-Dirac-cone on the surface
• A topological Dirac insulator in a quantum spin Hall phase : Experimental observation of first strong topological insulator
• Gate-Voltage Control of Chemical Potential and Weak Anti-localization in Bismuth Selenide
• Topological origin of subgap conductance in insulating bilayer graphene
• Two-dimensional Dirac fermions in a topological insulator: transport in the quantum limit
• Observation of topological surface state quantum Hall effect in an intrinsic three-dimensional topological insulator
• Observation of Dirac Holes and Electrons in a Topological Insulator
• Evidence of surface transport and weak anti-localization in single crystal of Bi2Te2Se topological insulator
• Low carrier concentration crystals of the topological insulator Bi${}_{2-x}$Sb${}_x$Te${}_{3-y}$Se${}_y$: a magnetotransport study
• Singular robust room-temperature spin response from topological Dirac fermions
• Anomalous thermal expansion of Sb${}_2$Te${}_3$ topological insulator
• Dirac states with knobs on: interplay of external parameters and the surface electronic properties of 3D topological insulators

Cited by in corpus (4)

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• Unconventional topological phase transition from semimetal to insulator in SnBi2Te4: Role of anomalous thermal expansion