Related papers: Unoccupied Topological States on Bismuth Chalcogen…
Topological surface-states can acquire an energy gap when time-reversal symmetry is broken by interfacing with a magnetic insulator. This gap has yet to be measured. Such topological-magnetic insulator heterostructures can host a quantized…
A topological insulator is characterized by spin-momentum locking on its boundary. The spin momentum locking on the surface of a three dimensional topological insulator leads to the existence of a non-trivial Berry's phase which leads to…
We revisit the problem of surface states in semiconductors with inverted band structures, such as $\alpha$-Sn and HgTe. We unravel the confusion that arose over the past decade regarding the origin of the surface states, their topological…
Topological insulators are a recently discovered class of materials with fascinating properties: While the inside of the solid is insulating, fundamental symmetry considerations require the surfaces to be metallic. The metallic surface…
We have performed angle-resolved photoemission spectroscopy on Pb(Bi1-xSbx)2Te4, which is a member of lead-based ternary tellurides and has been theoretically proposed as a candidate for a new class of three-dimensional topological…
Three dimensional topological insulator bismuth selenide (Bi2Se3) is expected to possess strong spin-orbit coupling and spin-textured topological surface states, and thus exhibit a high charge to spin current conversion efficiency. We…
We study the influence of the antiferromagnetic order on the surface states of topological insulators. We derive an effective Hamiltonian for these states, taking into account the spatial structure of the antiferromagnetic order. We obtain…
The vacuum of a band system, with respect to particles or holes, can become topologically nontrivial when the exceptional points of the non-hermitian Hamiltonian spread over the whole Brillouin zone. The coalescence of the eigenstates…
We report on the quenching of single Ni adatom moments on Te-terminated Bi2Te2Se and Bi2Te3 topological insulator surfaces. The effect becomes manifested as a missing X-ray magnetic circular dichroism for resonant L3,2 transitions into…
The opening of a band gap due to compressive uniaxial strain renders bulk HgTe a strong three-dimensional topological insulators with protected gapless surface states at any surface. By employing a six-band k.p model, we determine the spin…
Topologically protected edge states have been extensively studied in systems characterized by the topological invariants in band gaps (also called line gaps). In this study, we unveil a whole new form of edge states that transcends the…
Gapping of Dirac surface states through time reversal symmetry breaking may realize the axion insulator state in condensed matter. Despite tremendous efforts, only a few material systems fall in this category of intrinsic magnetic…
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…
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…
The recent theoretical prediction and experimental realization of topological insulators (TI) has generated intense interest in this new state of quantum matter. The surface states of a three-dimensional (3D) TI such as Bi_2Te_3, Bi_2Se_3…
The spin-polarized surface states in topological insulators offer unique transport characteristics that make them distinguishable from trivial conductors. Here, we detect the impact of these surface states in the topological insulator…
Binary bismuth chalcogenides Bi$_2$Se$_3$, Bi$_2$Te$_3$, and related materials are currently being extensively investigated as the reference topological insulators (TIs) due to their simple surface-state band dispersion (single Dirac cone)…
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 topological insulating phase results from inversion of the band gap due to spin-orbit coupling at an odd number of time-reversal symmetric points. In Bi$_2$Se$_3$, this inversion occurs at the $\Gamma$ point. For bulk Bi$_2$Se$_3$, we…
We study the microscopic origins of photocurrent generation in the topological insulator Bi$_2$Se$_3$ via time- and angle-resolved photoemission spectroscopy. We image the unoccupied band structure as it evolves following a circularly…