Anisotropy in the Magnetoresistance Scaling of BaFe$_2$(As$_{1-x}$P$_{x}$)$_2$

TL;DR

This study investigates the anisotropic magnetoresistance scaling in BaFe$_2$(As$_{1-x}$P$_{x}$)$_2$, revealing that the scaling depends solely on the out-of-plane magnetic field component, indicating a link to correlated spin and charge behavior.

Contribution

It extends previous work by analyzing tensor components under various magnetic field orientations, uncovering the specific out-of-plane field dependence of the scaling phenomenon.

Findings

Scaling involves only the out-of-plane magnetic field component.

The phenomenon is independent of the current direction.

Suggests magnetotransport is linked to spin-charge correlations, not quasiparticle motion.

Abstract

Theories of the strange metal, the parent state of many high temperature superconductors, invariably involve an important role for correlations in the spin and charge degrees of freedom. The most distinctive signature of this state in the charge transport sector is a resistance that varies linearly in temperature, but this phenomenon does not clearly point to one mechanism as temperature is a scalar quantity that influences every possible mechanism for momentum relaxation. In a previous work we identified an unusual scaling relationship between magnetic field and temperature in the in-plane resistivity of the unconventional superconductor BaFe$_2$(As$_{1-x}$P$_{x}$)$_2$, providing an opportunity to use the vector nature of the magnetic field to acquire additional clues about the mechanisms responsible for scattering in the strange metal state. Here we extend this work by investigating other components of the conductivity tensor under different orientations of the magnetic field. We find that the scaling phenomenon involves only the out-of-plane component of the magnetic field and is, strikingly, independent of the direction of the applied current. This suggests that the origin of the strange magnetotransport is in the action of the magnetic field on the correlated behavior of spin and charge degrees of freedom, rather than on the simple cyclotron motion of individual quasiparticles.