Topological charge Fano effect in multi-Weyl semimetals

TL;DR

This paper theoretically explores how the topological charge in multi-Weyl semimetals influences the Fano interference pattern in the bulk local density of states, revealing a topological charge-dependent Fano effect.

Contribution

It introduces the concept of a topological charge Fano effect, showing how the Fano profile evolves with the topological charge in multi-Weyl semimetals, and predicts a specific Fano parameter for the triple Weyl case.

Findings

Fano lineshape transitions from resonant to antiresonant with increasing topological charge J.

The Fano parameter for J=3 (triple Weyl) is predicted to be tan(360°/2J).

The topological charge modulates the Fano profile in the bulk density of states.

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-boundary" correspondence 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 lineshape evolves from resonant, typical for $J=1$ (single Weyl), towards antiresonant, extrapolating to the so-called hyper Weyl semimetals with $J\gg1$. Specially for the maximum case protected by the rotational symmetry $C_{2J=6}$, namely the $J=3$ (triple Weyl), which acquires asymmetric Fano profile, the Fano parameter absolute value is predicted to be $\tan(C_{2J=6})$, where $C_{2J}\equiv(360^{\circ}/2J)$ 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.