Mesoscopic pairing without superconductivity

Mesoscopic Effects in Superconductivity

Suppression of superconductivity in mesoscopic superconductors.

We propose a new boundary-driven phase transition associated with vortex nucleation in mesoscopic superconductors (of size of the order of, or larger than, the penetration depth). We derive the rescaling equations and we show that boundary effects associated with vortex nucleation lower the conventional transition temperature in mesoscopic superconductors by an amount which is a function of the...

Pairing superconductivity in two-dimensional CuO2.

The strongly correlated two-dimensional Cu0& layer is studied to identify the mechanism of possible pairing superconductivity. The correlative motions of 0 and Cu holes are treated by a reasonable mean-field theory, and we find that holes on oxygen sites couple strongly to Cu holes to form Cu-0 spin singlet pairs, which in turn interact strongly with the Cu resonating-valence-bond state and lea...

-pairing superconductivity in generalized Hubbard models

We consider generalized Hubbard models in arbitrary dimensions which have additional nearest-neigbour interactions. It is shown that in a large region of the parameter space these models have ground states of the-pairing type. These ground states exhibit oo-diagonal long-range order and are thus su-perconducting. In special cases the complete (T = 0) phase diagram can be obtained. The proposal ...

Inter-Band Pairing Theory of Superconductivity

A model for high temperature superconductors based on the idea of Cooper pairs comprised of electrons from different bands is studied. We propose that the two bands relevant for the cuprates are comprised of Cu dx2−y2, dz2 , planar O pσ, and apical O pz orbitals. Along the diagonal, kx = ky in the Brillouin zone, the two band Fermi surfaces may cross. We associate the optimal doping for the hig...