相关论文: Non-linear hybrid surface-defect states in defecti…
In this paper we present detailed study of the density of states near defects in Bi$_2$Se$_3$. In particular, we present data on the commonly found triangular defects in this system. While we do not find any measurable quasiparticle…
Several proposed applications and exotic effects in topological insulators rely on the presence of helical Dirac states at the interface between a topological and a normal insulator. In the present work, we have used low-energy…
The coexistence of topological bands around the Fermi level ($E_F$) and superconductivity provides a fundamental platform for exploring their interplay. However, few materials inherently display both properties. In this study, we…
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…
Based on group theoretical arguments we derive the most general Hamiltonian for the $\text{Bi}_2\text{Se}_3$-class of materials including terms to third order in the wave vector, first order in electric and magnetic fields, first order in…
A new type of topological spin-helical surface states was discovered in layered van der Waals bonded (SnTe)$_{n=2,3}$(Bi$_2$Te$_3$)$_{m=1}$ compounds which comprise two covalently bonded band inverted subsystems, SnTe and Bi$_2$Te$_3$,…
Semimetals, in which conduction and valence bands touch but do not form Fermi surfaces, have attracted considerable interest for their anomalous properties starting with the discovery of Dirac matter in graphene and other two-dimensional…
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…
Topological insulators are materials with an insulating bulk interior while maintaining gapless boundary states against back scattering. Bi$_2$Se$_3$ is a prototypical topological insulator with a Dirac-cone surface state around $\Gamma$.…
Topological insulators (TIs) are predicted to be composed of an insulating bulk state along with conducting channels on the boundary of the material. In Bi2Se3, however, the Fermi level naturally resides in the conduction band due to…
The results of ultra-high vacuum low-temperature scanning-tunneling microscopy (STM) and spectroscopy (STS) of atomically clean (111) surface of the topological insulator Bi$_2$Se$_3$ are presented. We observed several types of new…
The spin-helical surface states in three-dimensional topological insulator (TI), such as Bi2Se3, are predicted to have superior efficiency in converting charge current into spin polarization. This property is said to be responsible for the…
Topological surface states with intrinsic magnetic ordering in the MnBi$_2$Te$_4$(Bi$_2$Te$_3$)$_n$ compounds have been predicted to host rich topological phenomena including quantized anomalous Hall effect and axion insulator state. Here…
Whereas the concept of topological band-structures was developed originally for insulators with a bulk bandgap, it has become increasingly clear that the prime consequences of a non-trivial topology -- spin-momentum locking of surface…
We study the topologically non-trivial semi-metals by means of the 6-band Kane model. Existence of surface states is explicitly demonstrated by calculating the LDOS on the material surface. In the strain free condition, surface states are…
Spontaneously broken symmetry in the ground state of Bi-based topological materials can lead to promising Topological superconductors, such as Cu-Bi2Se3, Sr-Bi2Se3 and Nb-Bi2Se3. In recent studies, coexistence of multiple Fermi surface…
A three-dimensional strong-topological-insulator or -semimetal hosts topological surface states which are often said to be gapless so long as time-reversal symmetry is preserved. This narrative can be mistaken when surface state…
Many complex magnetic structures in a high-symmetry lattice can arise from a superposition of well-defined magnetic wave vectors. These "multi-q" structures have garnered much attention because of interesting real-space spin textures such…
As an ideal platform for studying interplays between symmetry, topology and magnetism, the magnetic topological insulator (MTI) MnBi2Te4 has attracted extensive attentions. However, its strong n-type intrinsic defects hinder the…
Three dimensional topological insulators are bulk insulators with $\mathbf{Z}_2$ topological electronic order that gives rise to conducting light-like surface states. These surface electrons are exceptionally resistant to localization by…