  While the Berezinskii-Kosterlitz-Thouless transition (BKT) has been under
intense scrutiny for decades, unambiguous experimental signatures in magnetic
systems remain elusive. Here, we investigate the interplay between electronic
and magnetic degrees of freedom near the BKT transition. Focusing on a metal
with easy-plane ferromagnetic order, we establish a framework that accounts
both for the coupling between the charge current and the flow of topological
magnetic defects and for electron scattering on their inhomogeneous spin
texture. We show that electron scattering is responsible for a
temperature-dependent magnetoresistance effect scaling as the density of the
topological defects, which is expected to increase dramatically above the BKT
transition temperature. Our findings call for further experimental
investigations.

Mesoscale and Nanoscale Physics