Bulk-boundary quantum oscillations in inhomogeneous Weyl semimetals

TL;DR

This paper investigates how intrinsic pseudo-magnetic fields in inhomogeneous Weyl semimetals influence bulk-boundary quantum oscillations, revealing a method to detect and measure these internal fields through oscillation period changes.

Contribution

It demonstrates that intrinsic pseudo-magnetic fields modify quantum oscillations in Weyl semimetals, providing a new way to detect and quantify internal inhomogeneities.

Findings

Intrinsic fields decrease oscillation periods

Oscillations can reveal the strength of intrinsic fields

Analytical traceability of the effect

Abstract

Weyl fermions in an external magnetic field exhibit the chiral anomaly, a non-conservation of chiral fermions. In a Weyl semimetal, a spatially inhomogeneous Weyl node separation causes similar effect by creating an intrinsic pseudo-magnetic field with an opposite sign for nodes of opposite chirality. In the present work we study the interplay of external and intrinsic fields. In particular, we focus on quantum oscillations due to bulk-boundary trajectories. When caused by an external field, such oscillations are a proven experimental technique to detect Weyl semimetals. We show that the intrinsic field leaves hallmarks on such oscillations by decreasing the period of the oscillations in an analytically traceable manner. The oscillations can thus be used to test the effect of an intrinsic field and to extract its strength.