Transport Signatures of a Kinetically Self-Trapped Nagaoka Polaron

Nagaoka polarons are canonical examples of kinetic magnetism. Although their spin structure is well understood, their transport remains unexplored. We compute the dynamical mobility of a single hole in the square-lattice $t$-model using resummation-based quantum Monte Carlo and analytic continuation. Upon cooling, an incoherent Drude-like response gives way to a finite-frequency peak as the dc mobility vanishes. The peak signals an internal mode of a hole confined by its ferromagnetic cloud. Our results establish transport as an incisive probe of polaron formation and kinetic self-trapping.