The 2D ferromagnetic Kondo model with classical corespins is studied for a hole doping up to x = 0.125 via unbiased Monte Carlo (MC) simulations. A canonical algorithm for finite temperatures is developed. We show that with realistic parameters for the manganites and at low temperatures, the double-exchange mechanism does not lead to phase separation on a two-dimensional lattice but rather stabilizes individual ferromagnetic polarons. A detailed analysis of unbiased MC results reveals that the polarons can be treated as independent particles. It is found that a simple polaron model perfectly describes the physics of the FM Kondo model. The ferromagnetic polaron picture provides an obvious explanation for the pseudogap in the one-particle spectral function Ak(ω) observed in the FM Kondo model.
@article{arxiv.cond-mat/0312394,
title = {Polaronic Aspects of the two-dimensional Ferromagnetic Kondo Model},
author = {M. Daghofer and W. Koller and H. G. Evertz and W. von der Linden},
journal= {arXiv preprint arXiv:cond-mat/0312394},
year = {2009}
}
Comments
15 pages, 9 figures; 1 new figure, additional references cited