Quantum decoherence in the spectral functions of undoped LaMnO3 - art. no.067204

We study the one hole spectral function in a model for LaMnO3 including bot h the effects of orbital ordering and the quantum decoherence due to the an tiferromagnetic coupling between the ferromagnetic layers. We find that the classical picture of a ferromagnetic polaron does not apply and free dispe rsion is replaced by rigid quasiparticles on the scale of magnetic excitati ons, while the spectra are dominated by the incoherent spectral weight at h igh energies. These results have important implications on the in-plane tra nsport and angular resolved photoemission in the manganites.