High Fermi velocities and small cyclotron masses in LaAlGe

TL;DR

This study reveals that LaAlGe, a type-II Weyl semimetal, exhibits extremely high Fermi velocities and small quasiparticle masses, with potential 2D electronic characteristics despite its 3D structure.

Contribution

It provides the first quantum oscillation measurements of LaAlGe, highlighting its unique electronic properties and possible 2D behavior without structural 2D features.

Findings

Very small quasiparticle masses detected

Very high Fermi velocities observed

Angular dependence suggests 2D character

Abstract

We report quantum oscillation measurements of LaAlGe, a Lorentz-violating type-II Weyl semimetal with tilted Weyl cones. Very small quasiparticle masses and very high Fermi velocities were detected at the Fermi surface. Whereas three main frequencies have been observed, angular dependence of two Fermi surface sheets indicates possible two-dimensional (2D) character despite the absence of the 2D structural features such as van der Waals bonds. Such conducting states may offer a good platform for low-dimensional polarized spin current in magnetic RAlGe (R = Ce, Pr) materials.