Anisotropic conductivity in magnetic topological insulators

Abstract

We study the surface conductivity of a three dimensional topological insulator doped with magnetic impurities. The spin-momentum locking of surface electrons makes their scattering from magnetic impurities anisotropic and the standard relaxation time approximation is not applicable. Using the semiclassical Boltzmann approach together with a generalized relaxation time scheme, we obtain closed forms for the relaxation times and analytic expressions for the surface conductivities of the system as functions of the bulk magnetization and the orientation of the aligned surface magnetic impurities. We show that the surface conductivity is anisotropic, and strongly depends both on the direction of the spins of magnetic impurities and on the magnitude of the bulk magnetization. In particular, we find that the surface conductivity has its minimum value when the spin of surface impurities are aligned perpendicular to the surface of TI, and therefore the backscattering probability is enhanced due to the magnetic torque exerted by impurities on the surface electrons.

arXiv comment6 pages, 4 Figures

References in corpus (18)

• Topological Insulators
• Topological insulators and superconductors
• Discovery (theoretical prediction and experimental observation) of a large-gap topological-insulator class with spin-polarized single-Dirac-cone on the surface
• Quantized Anomalous Hall Effect in Magnetic Topological Insulators
• Topological Crystalline Insulators
• Topological Surface States Protected From Backscattering by Chiral Spin Texture
• STM imaging of electronic waves on the surface of Bi${}_2$Te${}_3$: topologically protected surface states and hexagonal warping effects
• Semiclassical theories of the anomalous Hall effect
• Anomalous Hall effect in 2D Dirac band: link between Kubo-Streda formula and semiclassical Boltzmann equation approach
• Anisotropic transport in the two-dimensional electron gas in the presence of spin-orbit coupling
• Two-dimensional surface charge transport in topological insulators
• Transport in three-dimensional topological insulators: theory and experiment
• Anisotropic Magnetoresistance components in (Ga,Mn)As
• Surface magnetic ordering in topological insulators with bulk magnetic dopants
• Anisotropic current-induced spin accumulation in the two-dimensional electron gas with spin-orbit coupling
• Semiclassical framework for the calculation of transport anisotropies
• Exchange interaction and its tuning in magnetic binary chalcogenides
• Boltzmann conductivity of ferromagnetic graphene with magnetic impurities

Cited by in corpus (13)

• Transport in two-dimensional topological materials: recent developments in experiment and theory
• Magnetic-proximity-induced magnetoresistance on topological insulators
• Optical conductivity of three and two dimensional topological nodal line semimetals
• Impurity scattering on the surface of topological insulator thin films
• Voltage-driven Magnetization Switching via Dirac Magnetic Anisotropy and Spin--orbit Torque in Topological-insulator-based Magnetic Heterostructures
• Edelstein and inverse Edelstein effects caused by the pristine surface states of topological insulators
• Thermoelectric response of nodal-line semimetals: probe of the Fermi surface topology
• Transport in magnetically doped topological insulators: Effects of magnetic clusters
• Transport in two dimensional Rashba electron systems doped with interacting magnetic impurities
• The Anomalous Hall Effect in Magnetic Topological Insulators
• Doping-controlled surface conduction in topological insulators with warping effects
• Magneto-thermoelectricty of anisotropic two-dimensional materials
• Magnetic Interactions and Cluster Formation: Boosting Surface Thermopower in Topological Insulators