Physics and Astronomy Calendar

The origin of superconductivity in cuprates--the high-temperature superconductors discovered in 1987, remains a mystery. Unlike the conventional superconductors, the attraction between the electrons in cuprates may be mediated by magnetic excitations. I review the spin-fluctuation approach to the normal and superconducting states of the cuprates. Interaction of electrons -fermions -- with the continuum of spin bosonic excitations, lead to significant deviations of the cuprate normal-state properties from those of a standard Fermi liquid. Spin fluctuations lead also to an anisotropic pairing of electrons into the superconducting condensate. I will demonstrate a mutual feedback from the pairing on the fermions and bosons, and argue that some manifestations of the feedback are the fingerprints of spin-mediated pairing. Finally, I compare spin-fluctuation and phonon pairing mechanisms for the cuprates.