Quantm Magnetoresistance of the PrFeAsO oxypnictides

TL;DR

This paper investigates the unusual magnetic field dependence of transverse magnetoresistance in PrFeAsO, revealing linear MR at low temperatures linked to Dirac cone states and explaining it through a quantum model.

Contribution

It reports the first observation of linear magnetoresistance in PrFeAsO and attributes it to Dirac cone states, providing experimental evidence and theoretical explanation.

Findings

Large positive MR below spin density wave transition

Linear MR at low temperatures up to 14 T

Crossover from B-linear to B^2 dependence at higher temperatures

Abstract

We report the observation of an unusual $B$ dependence of transverse magnetoresistance (MR) in the PrFeAsO, one of the parent compound of pnictide superconductors. Below the spin density wave transition, MR is large, positive and increases with decreasing temperature. At low temperatures, MR increases linearly with $B$ up to 14 T. For $T$$\geq$40 K, MR vs $B$ curve develops a weak curvature in the low-field region which indicates a crossover from $B$ linear to $B^2$ dependence as $B$$\rightarrow$0. The $B$ linear MR originates from the Dirac cone states and has been explained by the quantum mechanical model proposed by Abrikosov.