相关论文: Hexagonal warping on optical conductivity of surfa…
A single two-dimensinoal Dirac fermion state has been recently observed on the surface of topological insulator Bi$_2$Te$_3$ by angle-resolved photoemission spectroscopy (ARPES). We study the surface band structure using $k \cdot p$ theory…
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…
The energy-momentum relationship of electrons on the surface of an ideal "Hydrogen-Atom" Topological Insulator forms a cone - a Dirac cone, which, when warped and distorted (no longer described by the Dirac equation), can lead to unusual…
Scanning tunneling spectroscopy studies on high-quality Bi$_2$Te$_3$ crystals exhibit perfect correspondence to ARPES data, hence enabling identification of different regimes measured in the local density of states (LDOS). Oscillations of…
Hexagonal warping provides an anisotropy to the dispersion curves of the helical Dirac fermions that exist at the surface of a topological insulator. A sub-dominant quadratic in momentum term leads to an asymmetry between conduction and…
We consider the transport properties of topological insulators surface states in the presence of uncorrelated point-like disorder, both in the classical and quantum regimes. The transport properties of those two-dimensional surface states…
We use laser-based Angle-Resolved Photoemission Spectroscopy (ARPES) to study how chemical substitution modifies the electronic properties of the Bi2(Se{1-x}Tex)3 (BiSeTe) family of topological insulators. We find that increasing the Te…
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…
We analyze the electronic structure of topological surface states in the family of magnetic topological insulators MnBi$_{2n}$Te$_{3n+1}$. We show that, at natural-cleavage surfaces, the Dirac cone warping changes its symmetry from…
We investigate the charge conductivity and current-induced spin polarization on the surface state of a three-dimensional topological insulator by including the hexagonal warping effect of Fermi surface both in classical and quantum…
We analyze the strong hexagonal warping of the Dirac cone of Bi$_2$Te$_3$ by angle-resolved photoemission. Along $\overline{\Gamma}$$\overline{\rm M}$, the dispersion deviates from a linear behavior meaning that the Dirac cone is warped…
Using density functional electronic structure calculations, we establish the consequences of surface termination and modification on protected surface-states of metacinnabar (beta-HgS). Whereas we find that the Dirac cone is isotropic and…
We investigate the spin and charge densities of surface states of the three-dimensional topological insulator $Bi_2Se_3$, starting from the continuum description of the material [Zhang {\em et al.}, Nat. Phys. 5, 438 (2009)]. The spin…
Topological insulators are bulk semiconductors that manifest in-gap massless Dirac surface states due to the topological bulk-boundary correspondence principle [1-3]. These surface states have been a subject of tremendous ongoing interest,…
Motivated by recent photoemission experiments on the surface of topological insulators we compute the spectrum of driven topological surface excitations in the presence of an external light source. We completely characterize the spectral…
Topological insulators in the Bi2Se3 family have an energy gap in the bulk and a gapless surface state consisting of a single Dirac cone. Low frequency optical absorption due to the surface state is universally determined by the fine…
The protected surface states of topological insulators (TIs) form gapless Dirac cones corresponding non-degenerate eigenstates with helical spin polarisation. The presence of a warping term deforms the isotropic cone of the most simple…
Adding a small subdominant quadratic in momentum term to a dominant linear Dirac dispersion curve affects conduction and valence band differently and leads to an hourglass-like structure for energy as a function of momentum. This applies to…
A magnetic torque method is proposed that probes the warping and mass gap of Dirac cone surface states in topological insulators like Bi2X3 (X=Se,Te). A rotating field parallel to the surface induces a paramagnetic moment in the helical…
Ultra-thin 3D topological insulators provide a stage to study the surface physics of such materials by minimizing the bulk contribution. Further, the experimentally verified snowflake like structure of the Fermi surface leads to a hexagonal…