相关论文: Reversible Engineering of Topological Insulator Su…
Three dimensional (3D) topological insulators are quantum materials with a spin-orbit induced bulk insulating gap that exhibit quantum-Hall-like phenomena in the absence of applied magnetic fields. The proposed applications of topological…
Three-dimensional topological insulators represent a new quantum phase of matter with spin-polarized surface states that are protected from backscattering. The static electronic properties of these surface states have been comprehensively…
The protected surface conduction of topological insulators is in high demand for the next generation of electronic devices. What is needed to move forward are robust settings where topological surface currents can be controlled by simple…
We study the photocurrent response of topological insulator surface states to circularly polarized light for arbitrary oblique incidence. We describe the surface states within a Dirac model, including several perturbations such as hexagonal…
From a leading-order unbiased renormalization group analysis we here showcase the emergence of superconductivity (including the topological ones) from purely repulsive electron-electron interactions in two-dimensional doped Dirac…
Three-dimensional doped Dirac insulators foster simply connected (in both topological and trivial regimes) and annular (deep inside the topological regime) Fermi surfaces (FSs) in the normal state, and allow on-site repulsions among…
Recent angle-resolved photoemission experiments have observed a proximity-induced superconducting gap in the helical surface states of a thin film of the 3D topological insulator Bi$_2$Se$_3$ grown on a superconducting NbSe$_2$ substrate.…
One of the most striking manifestations of electronic properties of topological insulators is the dependence of the photocurrent direction on the helicity of circularly polarized optical excitation. The helicity dependent photocurrents,…
Topological insulators are transformative quantum solids with immune-to-disorder metallic surface states having Dirac band structure. Ubiquitous charged bulk defects, however, pull the Fermi energy into the bulk bands, denying access to…
The topological state that emerges at the surface of a topological insulator (TI) and at the TI-substrate interface are studied in metal-hBN-Bi2Se3 capacitors. By measuring the RF admittance of the capacitors versus gate voltage, we extract…
We calculate the local density of states of two prototypical topological insulators (Bi$_2$Se$_3$ and Bi$_2$Te$_2$Se) as a function of distance from the surface within density functional theory. We find that, in the absence of disorder or…
Surfaces of topological insulators host a new class of states with Dirac dispersion and helical spin texture. Potential quantum computing and spintronic applications using these states require manipulation of their electronic properties at…
Topological insulators (TIs) are a new quantum state of matter. Their surfaces and interfaces act as a topological boundary to generate massless Dirac fermions with spin-helical textures. Investigation of fermion dynamics near the Dirac…
Spatially controlling the Fermi level of topological insulators and keeping its electronic states stable are indispensable processes to put this material into practical use for semiconductor spintronics devices. So far, however, such a…
We analytically calculate the intrinsic longitudinal and transverse optical conductivities of electronic systems which govern by a modified-Dirac fermion model Hamiltonian for materials beyond graphene such as monolayer MoS$_2$ and…
A 3D fermionic topological insulator has a gapless Dirac surface state protected by time-reversal symmetry and charge conservation symmetry. The surface state can be gapped by introducing ferromagnetism to break time-reversal symmetry,…
Starting from a three dimensional Hamiltonian, we study the optical properties of ultra-thin topological insulator slabs for which the coupling between Dirac fermions on opposite surfaces results in two degenerated gapped hyperbolic bands.…
We study transport and optical properties of the surface states which lie in the bulk energy gap of a thin-film topological insulator. When the film thickness is comparable with the surface state decay length into the bulk, the tunneling…
Topological insulators constitute a new and fascinating class of matter with insulating bulk yet metallic surfaces that host highly mobile charge carriers with spin-momentum locking. Remarkably, the direction and magnitude of surface…
Using time-, spin- and angle-resolved photoemission, we investigate the ultrafast spin dynamics of hot electrons on the surface of the topological insulator Bi$_2$Te$_3$ following optical excitation by fs-infrared pulses. We observe two…