Anomalous Surface Conductivity of Weyl Semimetals

Abstract

We calculate the surface dc conductivity of Weyl semimetals and show that it contains an anomalous contribution in addition to a Drude contribution from the Fermi arc. The anomalous part is independent of the surface scattering time, and appears at nonzero temperature and doping (away from the Weyl nodes), increasing quadratically with both. The nontrivial coupling between the surface and the bulk leads to an effective description on the surface that mimics an interacting twodimensional fluid in certain regimes of energy, even in the absence of any explicit scattering on the surface, and is responsible for the anomalous contribution. Remarkably, in a layered Weyl semimetal, the temperature dependent part of the surface conductivity at low temperatures is dominated by the anomalous response which can be probed experimentally to unravel this unusual behavior.

Transport, refraction and interface arcs in junctions of Weyl semimetals

“…In this situation, two Fermi arcs are present on the lateral surfaces at y = 0 and y = L and transport chiral current in the x direction. These states are responsible for the large surface contributions to electric transport in different geometries and setups [13,[59][60][61]. The transmission of the surface current carried by these states at the interface depends on the twist angle θ.…”