Parts | Days | Selection | Search | Downloads | Help
TT: Tiefe Temperaturen
TT 11: Postersitzung II (Metall-Isolator-Überg
änge, Phasenüberg
änge in Quantensystemen, Theorie: Systeme korrelierter Elektronen)
TT 11.29: Poster
Tuesday, March 25, 2003, 14:30–19:00, P2c, P2d
The optimal inhomogeneity for superconductivity — •Enrico Arrigoni1,2 and Steven A. Kivelson1 — 1Department of Physics, University of California, Los Angeles, California 90095, USA — 2Institut für Theoretische Physik und Astrophysik, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
We study the effect of nonuniform transverse couplings on a quasi-one dimensional superconductor described by a few coupled chains. We show that inhomogeneous couplings quite generally increase the superconducting (pairing) gap relative to the uniform system, but that beyond an “optimal” degree of inhomogeneity, they lead to a suppression of the tendency to phase coherence. The optimal conditions for superconductivity are derived. We also show that a delocalized phase can be obtained for a weakly disordered four-leg-ladder system with moderate repulsive interactions.
[1] E. Arrigoni and S. A. Kivelson, cond-mat/0212256