Hole spectral functions of LaMnO3
  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. 
Wei-Guo Yin (1,2), Hai-Qing Lin (1), and Chang-De Gong (2) ((1) The   Chinese University of Hong Kong, (2) Nanjing University)