Single-particle spectrum of the flux phase in the FM Kondo model

We investigate the 2D ferromagnetic Kondo lattice model for manganites with classical corespins at Hund's rule coupling JH=6, with antiferromagnetic superexchange 0.03=<J'=<0.05. We employ canonical and grand canonical unbiased Monte Carlo simulations and find paramagnetism, weak ferromagnetism and the flux phase, depending on doping and on J'. The observed single-particle spectrum in the flux phase differs from the idealized infinite lattice case, but agrees well with an idealized finite lattice case with thermal fluctuations