ANGLE-RESOLVED PHOTOEMISSION FROM YBA2CU3O7 - SIGNATURE OF CUO2 PLANEBANDS

We have carried out polarization dependent first principles calculatio ns of the angle-resolved photoemission (ARPES) spectra within the loca l-density approximation (LDA) based band theory framework for the YBa2 Cu3O7(001)-surface for k(parallel-to)-values along the GAMMAS line for all six possible ideal terminations of the lattice, together with par allel ARPES measurements. The theoretically predicted intensity and po larization dependence of the spectral feature arising from the CuO2 Pl ane bands near the Fermi energy is in remarkable overall accord with t he measurements, giving confidence in the interpretation of the experi mental data as being representative of the-bulk CuO2 bands. These resu lts suggest that the LDA-based wave-functions implicit in the theory r easonably describe the physical situation at least near the Fermi ener gy, some renormalization of the quasi-particle spectrum notwithstandin g. The question of surface termination is discussed; the present study favors the Y123(001)-surface to involve BaO topmost layer followed by the CuO2 plane layer.