Quantum oscillations from generic surface Fermi arcs and bulk chiral modes in Weyl semimetals

TL;DR

This paper advances understanding of quantum oscillations in Weyl semimetals by generalizing surface Fermi arc analysis, introducing new tools, and predicting a 'magic' magnetic field angle with experimental significance.

Contribution

It introduces semiclassical phase-space quantization and a layered numerical model to analyze quantum oscillations in generic Weyl semimetals, overcoming previous limitations.

Findings

Correctly reproduces quantum oscillations for curved Fermi arcs

Identifies a 'magic' magnetic field angle where oscillations are thickness-independent

Shows high-field oscillations persist despite disorder

Abstract

We re-examine the question of quantum oscillations from surface Fermi arcs and chiral modes in Weyl semimetals. By introducing two tools - semiclassical phase-space quantization and a numerical implementation of a layered construction of Weyl semimetals - we discover several important generalizations to previous conclusions that were implicitly tailored to the special case of identical Fermi arcs on top and bottom surfaces. We show that the phase-space quantization picture fixes an ambiguity in the previously utilized energy-time quantization approach and correctly reproduces the numerically calculated quantum oscillations for generic Weyl semimetals with distinctly curved Fermi arcs on the two surfaces. Based on these methods, we identify a 'magic' magnetic-field angle where quantum oscillations become independent of sample thickness, with striking experimental implications. We also analyze the stability of these quantum oscillations to disorder, and show that the high-field oscillations are expected to persist in samples whose thickness parametrically exceeds the quantum mean free path.