The effect of a locally repulsive interaction on s-wave superconductors

Autor(en)

Jean-Bernard Bru, W. de Siqueira Pedra

Abstrakt

The thermodynamic impact of the Coulomb repulsion on s-wave superconductors is analyzed via a rigorous study of equilibrium and ground states of the strong coupling BCS-Hubbard Hamiltonian. We show that the one-site electron repulsion can favor superconductivity at fixed chemical potential by increasing the critical temperature and/or the Cooper pair condensate density. If the one-site repulsion is not too large, a first or a second order superconducting phase transition can appear at low temperatures. The Meißner effect is shown to be rather generic but coexistence of superconducting and ferromagnetic phases is also shown to be feasible, for instance, near half-filling and at strong repulsion. Our proof of a superconductor-Mott insulator phase transition implies a rigorous explanation of the necessity of doping insulators to create superconductors. These mathematical results are consequences of "quantum large deviation" arguments combined with an adaptation of the proof of Størmer's theorem [1] to even states on the CAR algebra.

Organisation(en)

Mathematische Physik

Externe Organisation(en)

Johannes Gutenberg-Universität Mainz

Journal

Reviews in Mathematical Physics

Band

22

Seiten

233-303

Anzahl der Seiten

64

ISSN

0129-055X

DOI

https://doi.org/10.1142/S0129055X10003953

Publikationsdatum

2010

Peer-reviewed

Ja

ÖFOS 2012

103019 Mathematische Physik

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/89db3697-aeda-466c-a263-c958ce1db67a