Coherent direction-dependent valley transport in Dirac/Weyl semimetals

Abstract

We investigate the coherent transmission of collimated wave packets through an inversion-asymmetric electrostatic barrier in a Dirac or Weyl channel. For a barrier consisting of a vertical and an oblique interface, we show that forward- and backward-moving wave packets experience different Fermi-surface mismatch sequences, causing direction-dependent transport properties in channels with both isotropic and anisotropic energy dispersion. Furthermore, the simulation results reveal that the same barrier structure leads to valley-resolved direction-dependent transmission in tilted anisotropic systems. The proposed device is fully electrostatic, gate-tunable, and, in principle, compatible with a wide range of materials hosting Dirac/Weyl fermions.