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

作者：Bru Jean Bernard^*; de Pasquale Antonio Delgado; Pedra Walter de Siqueira

来源：Journal of Statistical Mechanics: Theory and Experiment , 2015, 2015(3): P03002.

DOI：10.1088/1742-5468/2015/03/P03002

• rigorous results in statistical mechanics
• Hubbard model (theory)
• quantum phase transitions (theory)

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.

• 出版日期2015-3