Magnetic field-induced non-trivial electronic topology in Fe_3−<i>x</i>GeTe₂

The anomalous Hall, Nernst, and thermal Hall coefficients of the itinerant ferromagnet Fe3−xGeTe2 display anomalies upon cooling that are consistent with a topological transition could induce deviations respect to Wiedemann–Franz (WF) law. This law has not yet been validated for transport variables, recent experimental studies yielding material-dependent results. Nevertheless, found, within our accuracy, satisfy WF magnetic fields μ0H applied along its c axis. Remarkably, large is also observed μ0H||a axis field aligned gradient chemical potential generated by gradients or electrical currents, configuration should lead their observation. These planar quantities found scale component magnetization ( M||), showing instead sharp decrease beyond μ0H||= 4 T required align moments μ0H||. We argue chiral spin structures associated Bloch domain walls field-dependent chirality produces novel type in absence interaction between currents. Locally captured Monte Carlo simulations incorporating small Dzyaloshinskii–Moriya biquadratic exchange interactions. observations reveal only new way detect expose excitations, but heat conversion expands current technological horizon thermoelectric energy applications.