1996/09/30 by Andreas Mielke · 3 citations
Physics and Astronomy · #Atomic and Subatomic Physics Research #Physics of Superconductivity and Magnetism #Quantum, superfluid, helium dynamics #cond-mat.supr-con
paper · pdf · doi:10.1002/andp.19975090305
17 pages, LaTeX2e, uses AMS-fonts, 5 ps-figures included. Replaced by a completely revised version that contains several new results on the renormalization of single particle energies, on the superconducting gap, and on the critical temperature
arxiv created 1996/12/17 · openalex publication_date 1997/01/01 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Abstract We study the problem of the phonon‐induced electron‐electron interaction in a solid. Starting with a Hamiltonian that contains an electron‐phonon interaction, we perform a similarity renormalization transformation to calculate an effective Hamiltonian. Using this transformation singularities due to degeneracies are avoided explicitly. The effective interactions are calculated to second order in the electronphonon coupling. It is shown that the effective interaction between two electrons forming a Cooper pair is attractive in the whole parameter space. For a simple Einstein model we calculate the renormalization of the electronic energies and the critical temperature of superconductivity.