Extremely large magnetoresistance from electron-hole compensation in the nodal loop semimetal ZrP$_2$

TL;DR

This study reveals that ZrP$_2$ exhibits extremely large, unsaturated magnetoresistance due to near-perfect electron-hole compensation, supported by ARPES measurements and band structure calculations showing a topological nodal loop.

Contribution

It is the first comprehensive investigation combining ARPES and magneto-transport to characterize ZrP$_2$'s electronic structure and magnetoresistance, highlighting its topological features and electron-hole balance.

Findings

ZrP$_2$ shows up to 40,000% magnetoresistance at 2 K.

ZrP$_2$ hosts a topological nodal loop near the Fermi level.

Magnetoresistance arises from electron-hole compensation.

Abstract

Several early transition metal dipnictides have been found to host topological semimetal states and exhibit large magnetoresistance. In this study, we use angle-resolved photoemission spectroscopy (ARPES) and magneto-transport to study the electronic properties of a new transition metal dipnictide ZrP$_2$. We find that ZrP$_2$ exhibits an extremely large and unsaturated magnetoresistance of up to 40,000 % at 2 K, which originates from an almost perfect electron-hole compensation. Our band structure calculations further show that ZrP$_2$ hosts a topological nodal loop in proximity to the Fermi level. Based on the ARPES measurements, we confirm the results of our calculations and determine the surface band structure. Our study establishes ZrP$_2$ as a new platform to investigate near-perfect electron-hole compensation and its interplay with topological band structures.