The ferromagnetic Kondo model with classical corespins is studied via unbiased Monte-Carlo simulations. We show that with realistic parameters for the manganites and at low temperatures, the double-exchange mechanism does not lead to phase separation in one-dimensional chains but rather stabilizes individual ferromagnetic polarons. Within the ferromagnetic polaron picture, the pseudogap in the one-particle spectral function A_k(\omega) can easily be explained. Ferromagnetic polarons also clear up a seeming failure of the double-exchange mechanism in explaining the comparable bandwidths in the ferromagnetic and paramagnetic phase. For our analysis, we extend a simplified model, the finite temperature uniform hopping approach (UHA), to include polarons. It can easily be evaluated numerically and provides a simple quantitative understanding of the physical features of the ferromagnetic Kondo model.
@article{arxiv.cond-mat/0301350,
title = {Magnetic Polarons in the 1D FM Kondo Model},
author = {Winfried Koller and Alexander Prüll and Hans Gerd Evertz and Wolfgang von der Linden},
journal= {arXiv preprint arXiv:cond-mat/0301350},
year = {2016}
}