Chiral electronics and effect of the external fields in topological semimetals*

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.

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 arXiv:2009.14753]. 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.