By fully relativistic first principles calculations, we predict that appropriate strain engineering of layered GaX (X=S, Se) leads to a new class of three-dimensional topological insulators with an excitation gap of up to 135 meV. Our results provide a new perspective on the formation of three-dimensional topological insulators. Band inversion can be induced by strain only, without considering ...

In and Ga impurities substitutional to Al in the oxide layer resulting from diffusion out of the substrate are identified as candidates for electron traps under inversion at In0.53Ga0.47As/Al2O3 interfaces. Through density-functional calculations, these defects are found to be thermodynamically stable in amorphous Al2O3 and to be able to capture two electrons in a dangling bond upon breaking bo...

2014 The energies of surface quantum levels of inversion layers in [0001] planes at the surface of tellurium, calculated from Shubnikov de Haas measurements, are compared with theoretical values obtained with the assumption of a triangular surface potential well. In the experimental concentration range, results are explained by the existence of a single sub-band, separated in two levels due to ...

The study of topological insulators has generally involved search of materials that have this property as an innate quality, distinct from normal insulators. Here we focus on the possibility of converting a normal insulator into a topological one by application of an external electric field that shifts different bands by different energies and induces a specific band inversion, which leads to a...

Employing density functional calculations we predict that SmS undergoes a topological phase transition from the trivial Kondo insulator (KI) black phase to a topological metallic gold phase under hydrostatic pressure. The underlying mechanism is the pressure-induced change of the 4f level from below to above the bottom of the 5d conduction band, leading to a d-f band inversion, a parity sign re...

We study the intravalley spin-orbit-mediated spin relaxation in monolayers of MoS2 within a two bands effective Hamiltonian. The intrinsic spin splitting of the valence band as well as a Rashba-like coupling due to the breaking of the out-of-plane inversion symmetry are considered. We show that, in the hole doped regime, the out-of-plane spin relaxation is not very efficient since the spin spli...

Among many approaches been made to improve interpretation of post stack seismic section, a great effort has been made aimed at increasing the resolution power of interpreting section and mapping the seismic reflection data to lithology. The purpose of sparse spike impedance inversion is aimed at this goal, to obtain a high-resolution impedance profile from low resolution or band limited seismic...

Photonic band gap (PBG) materials are attractive for cavity QED experiments because they provide extremely small mode volumes and are monolithic, integratable structures. As such, PBG cavities are a promising alternative to Fabry-Perot resonators. However, the cavity requirements imposed by QED experiments, such as the need for high Q (low cavity damping) and small mode volumes, present signifi...

Two-dimensional heterostructures with strong spin-orbit coupling have direct relevance to topological quantum materials and potential applications in spin-orbitronics. In this work, we report on novel quantum phenomena in [Pb2BiS3][AuTe2], a new 2D strong spin-orbit coupling heterostructure system. Transport measurements reveal the spin-related carrier scattering is at odds with the Abrikosov-G...

The topological invariants of band insulators are usually assumed to depend only on the connectivity between orbitals and not their intracell position (orbital embedding), which is a separate piece information in tight-binding description. For example, two dimensions, orbital embedding known change Berry curvature but Chern number. Here, we consider one-dimensional inversion-symmetric classifie...