论文信息 - Crossover from BCS‐superconductivity to Bose‐condensation

Crossover from BCS‐superconductivity to Bose‐condensation

Starting from a model of free Fermions in two dimensions with an arbitrary strong effective interaction, we derive a Ginzburg-Landau theory describing the crossover from BCS-superconductivity to Bose-condensation. We find a smooth crossover from the standard BCS-limit to a Gross-Pitaevski type equation for the order parameter in a Bose superfluid. The mean field transition temperature exhibits a maximum at a coupling strength, where the behaviour crosses over from BCS to Bose like with corres- ponding values of 2A,/Tc = 5 which are characteristic for high Tc superconductors.

W. Zwerger | M. Drechsler

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