Extremely high magnetoresistance and conductivity in the type-II Weyl semimetals WP2 and MoP2

TL;DR

This paper reports the discovery of extremely high magnetoresistance and conductivity in type-II Weyl semimetals WP2 and MoP2, highlighting their unique electronic properties and potential for advanced electronic applications.

Contribution

It provides experimental and theoretical analysis of WP2 and MoP2 as robust type-II Weyl semimetals with record-high magnetoresistance and low resistivity, advancing understanding of Weyl fermions in these materials.

Findings

WP2 exhibits magnetoresistance above 200 million % at 63 T and 2.5 K.

WP2 shows an extremely low residual resistivity of 3 nΩ·cm.

Transport measurements indicate large suppression of charge carrier backscattering.

Abstract

The peculiar band structure of semimetals exhibiting Dirac and Weyl crossings can lead to spectacular electronic properties such as large mobilities accompanied by extremely high magnetoresistance. In particular, two closely neighbouring Weyl points of the same chirality are protected from annihilation by structural distortions or defects, thereby significantly reducing the scattering probability between them. Here we present the electronic properties of the transition metal diphosphides, WP2 and MoP2, that are type-II Weyl semimetals with robust Weyl points. We present transport and angle resolved photoemission spectroscopy measurements, and first principles calculations. Our single crystals of WP2 display an extremely low residual low-temperature resistivity of 3 nohm-cm accompanied by an enormous and highly anisotropic magnetoresistance above 200 million % at 63 T and 2.5 K. These properties are likely a consequence of the novel Weyl fermions expressed in this compound. We observe a large suppression of charge carrier backscattering in WP2 from transport measurements.