A Unified Theory for the Cuprates, Iron-Based and Similar Superconducting Systems: Application for Spin and Charge Excitations in the Hole-Doped Cuprates

作者：Ashkenazi J^*

来源：Journal of Superconductivity and Novel Magnetism, 2009, 22(1): 3-11.

DOI：10.1007/s10948-008-0370-8

• Superconductivity
• Cuprates
• Iron
• Pnictides
• Auxiliary particles

A unified theory for the cuprates and the iron-based superconductors is derived on the basis of common features in their electronic structures, including quasi-two-dimensionality, and the large-U nature of the electron orbitals close to E(F) (smaller-U hybridized orbitals reside at bonding and antibonding states away from E(F)). Consequently, low-energy excitations are described in terms of auxiliary particles, representing combinations of atomic-like electron configurations, rather than electron-like quasiparticles. The introduction of a Lagrange-Bose field is necessary to enable the treatments of these auxiliary particles as bosons or fermions. The condensation of the bosons results in static or dynamical inhomogeneities, and consequently in a commensurate or an incommensurate resonance mode. The dynamics of the fermions determines the charge transport, and their strong coupling to the Lagrange-field bosons results in pairing and superconductivity. The calculated resonance mode in hole-doped cuprates agrees with the experimental results, and is shown to be correlated with the pairing gap on the Fermi arcs.

• 出版日期2009-1