  By use of the orbital t-J model, we calculate the photoemission spectra of
LaMnO3 using the exact diagonalization technique, and interpret our numerics
quite well in the orbital-polaron scenario where the scattering between holes
and orbital excitations is treated within the self-consistent Born
approximation. The quasiparticle bandwidth is found to be of the order of J and
t in the purely Coulombic and Jahn-Teller phononic model, respectively. We
suggest that angle-resolved photoemission spectroscopy experiments allow one to
distinguish between the orbital-polaron scenario and the Jahn-Teller polaron
scenario.
