Speaker: Yuriko Baba D'Agostino
Affiliation: Universidad Complutense de Madrid
Date: Tuesday, 16 February 2021 at 12:00
Location: Online seminar
Topological semimetals, such as Weyl and Dirac 3D semimetals, have attracted much interest in the last decade due to the promising new properties, especially related to their robust metallic surface states, called Fermi arcs. The effect of external perturbations such as electric fields or inversion-breaking terms enables the tuning of the surface states leading to non-trivial effects in transport properties.
In this talk we will introduce the topological materials and specifically the topological semimetals. Once the basis are set, we describe the effect of external fields on Weyl semimetals.
In particular, an electric field perpendicular to the surface generates a chiral dependent renormalization of the Fermi velocity in realistic low energy effective models [see Phys. Rev. B 100, 165105 (2019)]. On the other hand, the breaking of inversion symmetry produces a spin-orbit splitting that becomes non-negligible in a carefully designed sample [see New Journal of Physics 23(2) (2021)]. In a slab of topological semimetal, a substrate with heavy atoms should induce a strong and controllable Rashba spin-orbit coupling at the surface that will affect the Fermi arcs. In this case, the coupling between chiralities opens new possibilities for spin-dependent transport phenomena. Moreover, the effect of the impurities and the experimental feasibility will be discussed.