Large magnetoresistance in type-II Weyl semimetal WP$_2$

TL;DR

This study reveals that WP$_2$, a type-II Weyl semimetal, exhibits extremely large nonsaturating magnetoresistance, complex multiband electronic structure, and anisotropic Fermi surface features, with partial two-dimensional characteristics.

Contribution

It provides detailed magnetotransport measurements and quantum oscillation analysis of WP$_2$, highlighting its large magnetoresistance and electronic anisotropy, which are novel insights for type-II Weyl semimetals.

Findings

Magnetoresistance reaches 14,300% at 2 K and 9 T.

Quantum oscillations indicate multiband structure and Fermi surface anisotropy.

Partial two-dimensional character suggested by quantum oscillations despite non-layered structure.

Abstract

We report magnetotransport study on type-II Weyl semimetal WP$_2$ single crystals. Magnetoresistance (MR) exhibits a nonsaturating $H^{n}$ field dependence (14,300\% at 2 K and 9 T) whereas systematic violation of Kohler's rule was observed. Quantum oscillations reveal a complex multiband electronic structure. The cyclotron effective mass close to the mass of free electron m$_e$ was observed in quantum oscillations along $b$-axis, while reduced effective mass of about 0.5$m_e$ was observed in $a$-axis quantum oscillations, suggesting Fermi surface anisotropy. Temperature dependence of the resistivity shows a large upturn that cannot be explained by the multi-band magnetoresistance of conventional metals. Even though crystal structure of WP$_{2}$ is not layered as in transition metal dichalcogenides, quantum oscillations suggest partial two-dimensional character.