Topological charge Fano effect in multi-Weyl semimetals

Abstract

We theoretically analyze the Fano interference in a single impurity multi-Weyl semimetal hybrid system and show the emergence of the topological charge Fano effect in the bulk local density of states. In multi-Weyl semimetals, the number of Fermi arcs at the system boundaries is determined by the topological charge J, a direct consequence of the bulk-boundarycorrespondence principle. Analogously, we find that J also modulates the bulk Fano profile of the system with an embedded quantum impurity. Thus by increasing J, the Fano line shape evolves from resonant, typical for J=1 (single Weyl), towards antiresonant, extrapolating to the so-called hyper Weyl semimetals with J≫1. Specially for the maximum case protected by the rotational symmetry C2J=6, namely, the J=3 (triple Weyl), which acquires asymmetric Fano profile, the Fano parameter absolute value is predicted to be tan(C2J=6), where C2J(360∘/2J) defines the rotational angle. Hence, the Fano discretization in the J term introduces the topological charge Fano effect in multi-Weyl semimetals. We also suggest a transport device where we expect that the proposed Fano effect could be detected.