Phase shift of cyclotron orbits at type-I and type-II multi-Weyl nodes

TL;DR

This paper predicts how quantum oscillation phase shifts depend on the topological charge and tilt of Weyl fermions, revealing universal behavior in type-II multi-Weyl nodes and their magnetic breakthrough effects.

Contribution

It introduces a theoretical framework for understanding phase shifts in quantum oscillations for tilted and overtilted multi-Weyl fermions, including type-I and type-II cases.

Findings

Phase shift depends on topological charge in type-II Weyl fermions.

Magnetic breakthrough leads to universal phase shift cancellation.

The model captures tilt and topological charge effects on quantum oscillations.

Abstract

Quantum oscillations of response functions in high magnetic fields tend to reveal some of the most interesting properties of metals. In particular, the oscillation phase shift is sensitive to topological band features, thereby helping to identify the presence of Weyl fermions. In this work we predict characteristic parameter dependence of the phase shift for Weyl fermions with tilted and overtilted dispersion (type I and type II Weyl fermions) and an arbitrary topological charge (multi-Weyl fermions). For type-II Weyl fermions our calculations capture the case of magnetic breakthrough between the electron and the hole part of the dispersion. Here the phase shift turns out to depend only on the quantized topological charge due to cancellation of non-universal contributions from the electron and the hole part.