Thiago M. Melo | Searcharxiv

arXiv2017

Klein Tunneling of Spin Polarized Currents in HgTe Quantum Wells

We investigate the behavior of spin polarized currents in two-dimensional topological insulators (TI). Stationary solutions inside a HgTe/CdTe quantum well (QW) were obtained by Bernevig-Hughes-Zhang (BHZ) model modified by a electric and magnetic barrier inside a non-completely insulating bulk. An attenuated quantum spin Hall (QSH) effect occurs in the gaped region with an apparent Klein-like paradox. Even more interesting, for strong potential regime, the interaction between the quasiparticles and the barriers allows spin inversion of this electronic states in a distinct channel conduction. Thus, our findings suggest a mechanism to manipulated spin polarized currents in this system.

cond-mat.mes-hall↗

arXiv2015

Topological cutoff frequency in a slab waveguide: Penetration length in topological insulator walls

We study the propagation of electromagnetic (EM) waves in a slab-type waveguide which walls consist of three-dimensional topological insulator (3D TI). The results show that a cutoff frequency with topological stability limits the spectrum that propagates along the waveguide and are in agreement with experimental observations. Our approach also provides a way to measure the penetration length of surface metallic states in 3D TI.

cond-mat.mes-hall↗