d-Wave pairing driven by bipolaric modes related to giant electron-phonon anomalies in high-T-c superconductors

Author(s)

Bru, Jean-Bernard ; de Pasquale, Antonio Delgado ; Pedra, Walter de Siqueira

• Document type: Journal article
• Source: JOURNAL OF STATISTICAL MECHANICS-THEORY AND EXPERIMENT; v. N/A, p. 36-pg., 2015-03-01.

Abstract

Taking into account microscopic properties of most usual high-T-c superconductors, like cuprates, we define a class of microscopic model Hamiltonians for two fermions (electrons or holes) and one boson (bipolaron) on the two-dimensional square lattice. We establish that these model Hamiltonians can show d-wave pairing at the bottom of their spectrum, despite their space isotropy. This phenomenon appears when a 'giant electron-phonon anomaly' is present at the boundaries of the Brillouin zone ('half breathing' bond-stretching mode), as in doped cuprates. Our results can be used to derive effective electron-electron interactions mediated by bipolarons and we discuss regimes where the corresponding model is relevant for the physics of high-temperature superconductivity and can be mathematically rigorously studied. (AU)

• FAPESP's process: 13/13215-5 - Heat production in Infinitely extended fermion systems subjected to electric fields
• Grantee: Walter Alberto de Siqueira Pedra
• Support Opportunities: Regular Research Grants