| Abstract: | We study (inverse) photoemission from systemswith strong coupling of doped carriers to phonons.Using an adiabatic approximation, we develop a method forcalculating spectra. This method is particularly simple forsystems where the electron-phonon coupling can be neglected inthe initial state, e.g., the undoped t-J model. The theory then naturally explains why the electron-phonon coupling justleads to a broadening of spectra calculated without electron-phonon coupling, without changing the dispersion. This is in agreementwith recent angle-resolved photoemission spectroscopy (ARPES) on undoped cuprates, and it supports the interpretation in terms of strong electron-phonon interaction. The theory also shows thatfor systems with strong electron-phonon coupling in the initialstate, the result cannot in general be related to the spectrumobtained without electron-phonon coupling. |
