2007/07/31 by R. Heid, Rolf Heid, Klaus-Peter Bohnen +4 · 2 citations
Materials Science · Physics and Astronomy · #Iron-based superconductors research #Physics of Superconductivity and Magnetism #Superconductivity in MgB2 and Alloys #cond-mat.str-el #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevlett.100.137001
published as Phys. Rev. Lett. 100, 137001 (2008) · Figure 1 slightly revised, text shortened, accepted as a PRL
arxiv created 2008/02/21 · openalex publication_date 2008/03/31 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
Using the local density approximation and a realistic phonon spectrum we determine the momentum and frequency dependence of \ensuremathα2F(k,\ensuremathω) in YBa2Cu3O7 for the bonding, antibonding, and chain band. The resulting self-energy \ensuremathΣ is rather small near the Fermi surface. For instance, for the antibonding band the maximum of Re\ensuremathΣ as a function of frequency is about 7 meV at the nodal point in the normal state and the ratio of bare and renormalized Fermi velocities is 1.18. These values are a factor of 3--5 too small compared to the experiment showing that only a small part of \ensuremathΣ can be attributed to phonons. Furthermore, the frequency dependence of the renormalization factor Z(k,\ensuremathω) is smooth and has no anomalies at the observed kink frequencies which means that phonons cannot produce well-pronounced kinks in stoichiometric YBa2Cu3O7, at least, within the local density approximation.