Anisotropic in-plane resistivity and magnetoresistance of the detwinned BaFe₂As₂

We have measured the electrical resistivity and the magnetoresistance of detwinned BaFe₂As₂ single crystals in fields up to 16 Tesla. The temperature dependence of the resistivity shows a counterintuitive anisotropic behavior in the ab-plane, likely arising from the effect of the nematic susceptibility. Little magnetoresistance is observed at temperatures above the structural/magnetic transition, below which a huge in-plane magnetoresistance with an anisotropy is detected.