Related papers: Dirac cone shift of a passivated topological Bi2Se…
Using angle-resolved photoelectron spectroscopy we investigate the surface electronic structure of the three-dimensional topological insulator (TI) Sb2Te3(0001). Our data show the presence of a topological surface state in the bulk energy…
Using low temperature scanning tunneling spectroscopy, we probe the Landau levels of the topologically protected state of Sb2Te3(0001) after in-situ cleavage of a single crystal. Landau levels are visible for magnetic fields B > 2 T at…
The magnitude of electron spin polarization in topologically protected surface states is an important parameter with respect to spintronics applications. In order to analyze the warped spin texture in Bi$_2$Te$_3$ thin films, we combine…
State-of-the-art topological devices require the use topological surface states to drive electronic transport. In this study, we examine a tunable topological system, $Ge(Bi_{x}Sb_{1-x})_{2}Te_{4}$, for a range of 'x' values from 0 to 1,…
Topological superconductors should be able to provide essential ingredients for quantum computing, but are very challenging to realize. Spin-orbit interaction in iron-based superconductors opens the energy gap between the $p$-states of…
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…
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…
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…
Topological insulators are novel macroscopic quantum-mechanical phase of matter, which hold promise for realizing some of the most exotic particles in physics as well as application towards spintronics and quantum computation. In all the…
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…
Optical measurements and band structure calculations are reported on 3D Dirac materials. The electronic properties associated with the Dirac cone are identified in the reflectivity spectra of Cd$_3$As$_2$ and Na$_3$Bi single crystals. In…
Elastic strain has the potential for a controlled manipulation of the band gap and spin-polarized Dirac states of topological materials, which can lead to pseudo-magnetic-field effects, helical flat bands and topological phase transitions.…
Using high resolution spin- and angle-resolved photoemission spectroscopy, we map the electronic structure and spin texture of the surface states of the topological insulator Sb2Te3. In combination with density functional calculations…
We have studied the energy dispersion of the Dirac bands of the topological insulator Bi2Se3 at large parallel momenta using a setup for laser-based time-resolved momentum microscopy with 6 eV probe-photons. Using this setup, we can probe…
We measure the temperature-dependent carrier density and resistivity of the topological surface state of thin exfoliated Bi2Se3 in the absence of bulk conduction. When the gate-tuned chemical potential is near or below the Dirac point the…
The close approach of the Fermi energy EF of a Dirac semimetal to the Dirac point ED uncovers new physics such as velocity renormalization,1,2,3 and the Dirac plasma 4,5 at |EF -ED| < kBT, where kBT is the thermal energy. In graphene,…
We investigate the surface state of Bi$_2$Te$_3$ using angle resolved photoemission spectroscopy (ARPES) and transport measurements. By scanning over the entire Brillouin zone (BZ), we demonstrate that the surface state consists of a single…
Transport due to spin-helical massless Dirac fermion surface state is of paramount importance to realize various new physical phenomena in topological insulators, ranging from quantum anomalous Hall effect to Majorana fermions. However, one…
Three-dimensional topological insulators are characterized by the presence of a bandgap in their bulk and gapless Dirac fermions at their surfaces. New physical phenomena originating from the presence of the Dirac fermions are predicted to…
The topological insulator Bi2Se3 shows a Raman scattering response related to topologically protected surface states amplified by a resonant interband transition. Most significantly this signal has a characteristic Lorentzian lineshape and…