Franck-Condon-Broadened Angle-Resolved Photoemission Spectra Predicted in LaMnO₃

The sudden photohole of least energy created in the photoemission process is a vibrationally excited state of a small polaron. Therefore the photoemission spectrum in LaMnO₃ is predicted to have multiple Franck-Condon vibrational sidebands. This generates an intrinsic line broadening ≈0.5 eV. The photoemission spectral function has two peaks whose central energies disperse with bandwidth ≈1.2 eV. Signatures of these phenomena are predicted to appear in angle-resolved photoemission spectra.