Phase of quantum oscillation in Weyl semimetals

TL;DR

This paper analyzes the phase of quantum oscillations in Weyl semimetals, revealing a universal constant value that aids in identifying Weyl points through experimental measurements.

Contribution

It demonstrates that the constant b3 in the semiclassical quantization condition is universally zero, regardless of the Weyl spectrum tilt, clarifying the interpretation of quantum oscillation phases.

Findings

The constant b3 equals zero for Weyl semimetals.

Quantum oscillation phase measurements can locate Weyl points.

The Berry phase differs from c in these systems.

Abstract

We consider the semiclassical quantization condition for the energy of an electron in a magnetic field in the case when the electron orbit lies on a Fermi-surface pocket surrounding the Weyl point of a topological semimetal and analyze the constant $\gamma$ appearing in this condition. It is shown that this constant has the universal value, $\gamma=0$, independent of the tilt of the Weyl spectrum. Since the constant $\gamma$ for an extremal cross section of the Fermi surface determines the phase of quantum oscillations, this result explains why measurements of the phase permit one to find Weyl points in crystals even though the extremal cross section of the pocket does not pass through this point, and the appropriate Berry phase of the orbit differs from $\pi$.