Anisotropy of Electrical Transport in Pnictide Superconductors Studied Using Monte Carlo Simulations of the Spin-Fermion Model

TL;DR

This study uses Monte Carlo simulations of a spin-fermion model to investigate electrical anisotropy in pnictide superconductors, reproducing experimental resistance features and revealing the role of spin and orbital order.

Contribution

It introduces a detailed Monte Carlo simulation approach for the three-orbital spin-fermion model, capturing anisotropic transport properties in Fe-based superconductors.

Findings

Resistance vs. temperature curves match experimental data.

Low-temperature anisotropy observed in simulations.

Peak in resistance at magnetic transition temperature.

Abstract

The undoped three-orbital spin fermion model for the Fe-based superconductors is studied via Monte Carlo techniques in two-dimensional clusters. At low temperatures, the magnetic and one-particle spectral properties are in good agreement with neutron and photoemission experiments. Our most important results are the resistance vs. temperature curves that display all the features experimentally observed in BaFe$_2$As$_2$ detwinned single crystals (under uniaxial stress), including a low-temperature anisotropy between the two directions followed by a peak at the magnetic ordering temperature, here induced by short-range spin order and concomitant Fermi Surface orbital order.