Related papers: Probing spatial extent of topological surface stat…
Topological photonics and acoustics have recently garnered wide research interests for their topological ability to manipulate the light and sound at surfaces. Conventionally, the supercell technique is the standard approach to calculating…
The paper examines weak localization (WL) of surface states with a quadratic band crossing in topological crystalline insulators. It is shown that the topology of the quadratic band crossing point dictates the negative sign of the WL…
A two-dimensional (2D) topological insulator (TI) exhibits the quantum spin Hall (QSH) effect, in which topologically protected spin-polarized conducting channels exist at the sample edges. Experimental signatures of the QSH effect have…
Topological insulators have surface states with unique spin-orbit coupling. With impurities on the surface, the quasiparticle interference pattern is an effective way to reveal the topological nature of the surface states, which can be…
We present a quantitative microscopic theory of the disorder- and phonon-induced coupling between surface and bulk states in topological insulator (TI) films. We find a simple structure for the surface-to-bulk scattering matrix elements and…
We use optical pump--THz probe spectroscopy at low temperatures to study the hot carrier response in thin Bi$_2$Se$_3$ films of several thicknesses, allowing us to separate the bulk from the surface transient response. We find that for…
Stanene was proposed to be a quantum spin hall insulator containing topological edges states and a time reversal invariant topological superconductor hosting helical Majorana edge mode. Recently, experimental evidences of existence of…
The topology of an object describes global properties that are insensitive to local perturbations. Classic examples include string knots and the genus (number of handles) of a surface: no manipulation of a closed string short of cutting it…
Quantum information measures are proposed to analyze the structure of near-gap electronic states in HgTe quantum wells in a strip geometry $(x,y)\in (-\infty,\infty)\times [0,L]$ of finite width $L$. This allows us to establish criteria for…
A new method for the experimental study of ionization loss of relativistic negatively charged particles moving in a crystal in the channeling regime using a semiconductor surface-barrier detector with smoothly tunable thickness of the…
Epitaxial thin films of (Sn$_{x}$Pb$_{1-x}$)$_{1-y}$In$_{y}$Te were successfully grown by molecular-beam-epitaxy (MBE) in a broad range of compositions (0 $\leq$ x $\leq$ 1, 0 $\leq$ y $\leq$ 0.23). We investigated electronic phases of the…
Electronic transport experiments involving the topologically protected states found at the surface of Bi2Se3 and other topological insulators require fine control over carrier density, which is challenging with existing bulk-doped material.…
The massless Dirac fermions residing on the surface of three-dimensional topological insulators are protected from backscattering and cannot be localized by disorder, but such protection can be lifted in ultrathin films when the…
Topological insulator lie at the forefront of condensed matter physics. However strong disorder can destroy the topological states and make all states become localized. In this paper, we investigate the competition between topology and…
Topologically nontrivial band structure of a material may give rise to special states that are confined to the material's boundary and protected against disorder and scattering. Quantum spin Hall effect (QSHE) is a paradigmatic example of…
We report magnetotransport studies on a gated strained HgTe device. This material is a threedimensional topological insulator and exclusively shows surface state transport. Remarkably, the Landau level dispersion and the accuracy of the…
Motivated by the transmission of topological surface states through atomic scale steps, we study the transport of gapless Dirac fermions on hyperbolic surfaces. We confirm that, independent of the curvature of the hyperbolae and the…
The surface area of Bi2Te3 thin films was increased by introducing nanoscale porosity. Temperature dependent resistivity and magnetotransport measurements were conducted both on as-grown and porous samples (23 and 70 nm). The longitudinal…
Quantum entanglement is a particularly useful characterization of topological orders which lack conventional order parameters. In this work, we study the entanglement in topologically ordered states between two arbitrary spatial regions,…
We report transport studies on the layered van der Waals topological crystalline insulator Ta$_2$Pd$_3$Te$_5$. The temperature-dependent resistance at high temperature is dominated by a bulk insulating gap and tend to saturate at low…