Importance of many-body effects to the spectral function of 1T-TiTe2 -: art. no. 045116

We present a line-shape analysis of high-resolution angle-resolved photoemission spectra of the quasi-two-dimensional system 1T-TiTe2, measured with an energy resolution of 5 meV and an angular resolution of 0.3 degrees. The analysis is based on the spectral function, containing contributions from electron-phonon and electron-electron scattering and a remaining contribution from electron-impurity interaction. Our results show that the low-temperature spectra near k(F) can only be adequately described by taking all three contributions into account. In particular, the electron-phonon interaction has a distinct effect on the shape of the spectral function close to the Fermi level, making the influence of the electron-electron interaction hardly visible for this material. Furthermore, we discuss the importance of the sample quality and the influence of impurities on the photoemission spectra.