Extremely large magnetoresistance from electron-hole compensation in the nodal-loop semimetal ZrP 2

Several early transition metal dipnictides (TMDPs) have been found to host topological semimetal states and exhibit large magnetoresistance (MR). In this paper, we use angle-resolved photoemission spectroscopy (ARPES) and magnetotransport to study the electronic properties of a TMDP ${\mathrm{ZrP}}_{2}$. We find that ${\mathrm{ZrP}}_{2}$ exhibits an extremely large and unsaturated MR of up to 40 000% at 2 K, which originates from an almost perfect electron-hole (e-h) compensation. Our band structure calculations further show that ${\mathrm{ZrP}}_{2}$ 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. This paper establishes ${\mathrm{ZrP}}_{2}$ as a platform to investigate near-perfect e-h compensation and its interplay with topological band structures.