Surface state transport in double-gated and magnetized topological insulators with hexagonal warping effects

Abstract

We explore the scattering of Dirac electrons in a double-gated topological insulator in the presence of magnetic proximity effects and warped surface states. It is found that a magnetic field can shift the Dirac cone in momentum space and deform the constant-energy contour, or opens up a band gap at the Dirac point, depending on the magnetization orientation. The double gate voltage induces quantum wells and/or quantum barriers on the surface of topological insulators, generating surface resonant tunnelling states. It is found that the hexagonal warping effect can increase the electronic transport at high energies when the constant-energy contour exhibits a snowflake shape. The energy-dependent conductances in the parallel and antiparallel magnetic configurations exhibit out-of-phase oscillations due to the quantum interference of propagating waves in the region between the two magnetized segments. Although the conductance spectrum of the double-well structure is higher than that of the double-barrier structure, the magnetoresistance ratio versus the separation distance between the two magnetized barriers exhibits pronounced oscillations due to the resonant tunnelling states. We show that the surface state transport can be controlled by the exchange field and gate voltage without breaking time reversal symmetry, suggesting that the double gated and magnetized topological insulators can be utilized to achieve a large magnetoresistance ratio with a tunable sign.

arXiv comment8 pages, 8 figures

References in corpus (23)

• Topological Insulators
• Topological insulators and superconductors
• Chiral tunneling and the Klein paradox in graphene
• Topological Insulator Materials
• Hexagonal Warping Effects in the Surface States of Topological Insulator Bi${}_2$Te${}_3$
• Room temperature spin-orbit torque switching induced by a topological insulator
• Room temperature magnetization switching in topological insulator-ferromagnet heterostructures by spin-orbit torques
• Impurity-induced states on the surface of 3D topological insulators
• Spin and Charge Transport on the Surface of a Topological Insulator
• Current-nonlinear Hall effect and spin-orbit torque magnetization switching in a magnetic topological insulator
• Electrical detection of the spin polarization due to charge flow in the surface state of the topological insulator Bi_1.5 Sb_0.5 Te_1.7 Se_1.3
• Room Temperature Electrical Detection of Spin Polarized Currents in Topological Insulators
• Spin-Polarized Tunneling Study on Spin-Momentum Locking in the Topological Insulators
• Relationship between Fermi-Surface Warping and Out-of-Plane Spin Polarization in Topological Insulators: a View from Spin-Resolved ARPES
• Magnetic-proximity-induced magnetoresistance on topological insulators
• Magnetoelectric Response of the Time-Reversal Invariant Helical Metal
• Hexagonal warping on optical conductivity of surface states in Topological Insulator Bi_{2}Te_{3}
• Surface charge conductivity of topological insulator in a magnetic field: effect of hexagonal warping
• Surface states scattering from a step defect in topological insulator Bi_{2}Te_{3}
• Gate voltage controlled electronic transport through a ferromagnet/normal/ferromagnet junction on the surface of a topological insulator
• Tunnel magnetoresistance in double spin filter junctions
• Spin-dependent resonant tunneling in ZnSe/ZnMnSe heterostructures
• Anisotropic Fabry-Pérot resonant states confined within nano-steps on the topological insulator surface

Cited by in corpus (3)

• Electron beam splitting at topological insulator surface states and a proposal for electronic Goos-Hanchen shift measurement
• Doping-controlled surface conduction in topological insulators with warping effects
• Electron scattering in a superlattice of line defects on the surface of topological insulators