Hexagonal warping on spin texture, Hall conductivity and circular dichroism of Topological Insulator

Abstract

The topological protected electronic states on the surface of a topological insulator can progressively change their Fermi cross-section from circular to a snowflake shape as the chemical potential is increased above the Dirac point because of an hexagonal warping term in the Hamiltonian. Another effect of warping is to change the spin texture which exists when a finite gap is included by magnetic doping, although the in-plane spin component remains locked perpendicular to momentum. It also changes the orbital magnetic moment, the matrix element for optical absorption and the circular dichroism. We find that the Fermi surface average of z-component of spin is closely related to the value of the Berry phase. This holds even when the Hamiltonian includes a subdominant non-relativistic quadratic in momentum term (which provides particle-hole asymmetry) in addition to the dominant relativistic Dirac term. There is also a qualitative correlation between $⟨S_z⟩$ and the dichroism. For the case when the chemical potential falls inside the gap between valence and conduction band, the Hall conductivity remains quantized and unaffected in value by the hexagonal warping term.

arXiv comment10 figures, accepted in PRB

References in corpus (26)

• Topological Insulators
• Topological insulators and superconductors
• Coupled spin and valley physics in monolayers of MoS2 and other group-VI dichalcogenides
• Valley contrasting physics in graphene: magnetic moment and topological transport
• First observation of Spin-Momentum Helical Locking in Bi2Se3 and Bi2Te3, demonstration of Topological-Order at 300K and a realization of topological-transport-regime
• First direct observation of Spin-textures in Topological Insulators : Spin-resolved ARPES as a probe of topological quantum spin Hall effect and Berry's phase
• Valley Dependent Optoelectronics from Inversion Symmetry Breaking
• Model Hamiltonian for Topological Insulators
• Magneto-optical conductivity in Graphene
• Hexagonal Warping Effects in the Surface States of Topological Insulator Bi${}_2$Te${}_3$
• Topological Phase Transition and Texture Inversion in a Tunable Topological Insulator
• Hedgehog Spin-texture and Berry's Phase tuning in a Magnetic Topological Insulator
• On the universal AC optical background in graphene
• Valley-Spin Polarization in the Magneto-Optical Response of Silicene and Other Similar 2D Crystals
• Observation of a warped helical spin-texture in Bi${}_2$Se${}_3$ from circular dichroism angle-resolved photoemission spectroscopy
• Topological Berry phase and semiclassical quantization of cyclotron orbits for two dimensional electrons in coupled band models
• Anomalous Absorption Line in the Magneto-Optical Response of Graphene
• Dirac electronic states in graphene systems: Optical spectroscopy studies
• Quantum oscillations and Berry's phase in topological insulator surface states with broken particle-hole symmetry
• Novel Spin-texture on the warped Dirac-cone surface states in topological insulators
• Relationship between Fermi-Surface Warping and Out-of-Plane Spin Polarization in Topological Insulators: a View from Spin-Resolved ARPES
• Magneto-optical conductivity in a topological insulator
• Effect of electron-phonon interaction on spectroscopies in graphene
• Hexagonal warping on optical conductivity of surface states in Topological Insulator Bi_{2}Te_{3}
• Magneto-optical conductivity in graphene including electron-phonon coupling
• Measuring the Chern number with quantum oscillations

Cited by in corpus (16)

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• Quantized photonic spin Hall effect in graphene
• Linear photogalvanic effect in surface states of topological insulators
• Photo-induced tunable Anomalous Hall and Nernst effects in tilted Weyl Semimetals using Floquet theory
• Magnetic dipole ordering in resonant dielectric metasurfaces
• Giant Inverse Rashba-Edelstein Effect: Application to Monolayer OsBi${}_2$
• Particle-Hole Asymmetry in Gapped Topological Insulator Surface States
• The tuning of light-matter coupling and dichroism in graphene for enhanced absorption: Implications for graphene-based optical absorption devices
• Nonlinear response in a non-centrosymmetric topological insulator
• Trigonal warping induced terraced spin texture and nearly perfect spin polarization in graphene with Rashba effect
• Anomalous thermoelectric properties of a Floquet topological insulator with spin momentum non-orthogonality
• Spin texture of an irradiated warped topological insulator surface
• Effect of Perturbative Hexagonal Warping on Quantum Capacitance in Ultra-Thin Topological Insulators
• Reconstructing the wavefunction of magnetic topological insulators MnBi2Te4 and MnBi4Te7 using spin-resolved photoemission
• Topological surface states hybridized with bulk states of Bi-doped PbSb2Te4 revealed in quasiparticle interference
• Hexagonal Warping Control of Exceptional Points in Topological Insulator--Ferromagnetic Heterojunctions