2005/03/14 by Joerg Buenemann, Jörg Bünemann, Florian Gebhard +4 · 14 citations
Materials Science · Physics and Astronomy · #BCS theory #Hubbard model #Organic and Molecular Conductors Research #Pairing #Perturbation theory (quantum mechanics) #Physics #Physics of Superconductivity and Magnetism #Quantum and electron transport phenomena #Quantum mechanics #Statistical physics #Superconductivity #Wave function #cond-mat.str-el
paper · pdf · doi:10.1088/0953-8984/17/25/007
published in Journal of Physics Condensed Matter 17(25), 3807-3814 (IOP Publishing) · 10 pages, 2 figures
arxiv created 2005/03/14 · openalex publication_date 2005/06/10 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We investigate the electronic and superconducting properties of a negative-U Hubbard model. For this purpose we evaluate a recently introduced variational theory based on Gutzwiller-correlated BCS wavefunctions. We find significant differences between our approach and standard BCS theory, especially for the superconducting gap. For small values of |U|, we derive analytical expressions for the order parameter and the superconducting gap which we compare to exact results from perturbation theory.