Related papers: Dirac cone shift of a passivated topological Bi2Se…
TlBiSSe is a rare realization of a 3D semimetal with a conically dispersing band that has an optical response which is well isolated from other contributions in a broad range of photon eneries. We report optical and magneto-optical…
Topological insulators represent a new state of matter where the topological nature of the bulk bands dictates the existence of a surface state with unique properties. These materials are predicted to host exotic states such as Majorana…
This study is devoted to the profound implications of tilted Dirac cones on the quantum transport properties of two-dimensional (2D) Dirac materials. These materials, characterized by their linear conic energy dispersions in the vicinity of…
Dirac points lie at the heart of many fascinating phenomena in condensed matter physics, from massless electrons in graphene to the emergence of conducting edge states in topological insulators [1, 2]. At a Dirac point, two energy bands…
Individual relaxation dynamics of electrons and holes in optically pumped semiconductors is rarely observed due to their overlap. Here we report the individual dynamics of long-lived (~200 mks) holes observed at room temperature in a 10 nm…
Electrons with a linear energy/momentum dispersion are called massless Dirac electrons and represent the low-energy excitations in exotic materials like Graphene and Topological Insulators (TIs). Dirac electrons are characterized by notable…
Three-dimensional topological insulators host surface states with linear dispersion, which manifest as a Dirac cone. Nanoscale transport measurements provide direct access to the transport properties of the Dirac cone in real space and…
In the presence of certain symmetries, three-dimensional Dirac semimetals can harbor not only surface Fermi arcs, but also surface Dirac cones. Motivated by the experimental observation of rotation-symmetry-protected Dirac semimetal states…
We study the transport properties of Dirac fermions in a graphene-based double-barrier structure composed of two tilted-cone regions separated by a central pristine graphene region. Using the transfer matrix method, we systematically…
To date transport measurements of topological insulators have been dominated by the conductivity of the bulk, leading to substantial difficulties in resolving the properties of the surface. To this end, we use high magnetic field, rf- and…
We study Bi2Se3 by polarization-dependent angle-resolved photoemission spectroscopy (ARPES) and density-functional theory slab calculations. We find that the surface state Dirac fermions are characterized by a layer-dependent entangled…
Twisted bilayer graphene is an excellent example of highly correlated system demonstrating a nearly flat electron band, the Mott transition and probably a spin liquid state. Besides the one-electron picture, analysis of Dirac points is…
The emergence of topological order in graphene is in great demand for the realization of quantum spin Hall states. Recently, it is theoretically proposed that the spin textures of surface states in topological insulator can be directly…
Arc-like topological surface states, i.e., surface Fermi arcs, have long been recognized as the hallmark of Dirac semimetals. However, recent theories suggest that the surface Fermi arcs could evolve into closed Fermi loops, akin to surface…
The unoccupied states in topological insulators Bi_2Se_3, PbSb_2Te_4, and Pb_2Bi_2Te_2S_3 are studied by the density functional theory methods. It is shown that a surface state with linear dispersion emerges in the inverted conduction band…
We have designed three-dimensional models of topological insulator thin films, showing a tunability of the odd number of Dirac cones on opposite surfaces driven by the atomic-scale geometry at the boundaries. This enables creation of a…
Strong Coulomb repulsion is predicted to open a many-body charge gap at the Dirac point of graphene, transforming the semimetal into a Mott insulator. However, this correlated insulating phase has remained inaccessible in pristine graphene,…
Periodic driving of a quantum system can significantly alter its energy bands and even change the band topology, opening a completely new avenue for engineering novel quantum matter. Although important progress has been made recently in…
Two-dimensional (2D) massless Dirac electrons appear on a surface of three-dimensional topological insulators. The conductivity of such a 2D Dirac electron system is studied for strong topological insulators in the case of the Fermi level…
We analyze the magneto-optical conductivity (and related magnitudes like transmittance and Faraday rotation of the irradiated polarized light) of some elemental two-dimensional Dirac materials of group IV (graphene analogues, buckled…