2 research outputs found
Nonperturbative XY-model approach to strong coupling superconductivity in two and three dimensions
For an electron gas with delta-function attraction we investigate the
crossover from weak- to strong-coupling supercoductivity in two and three
dimensions. We derive analytic expressions for the stiffness of phase
fluctuations and set up effective XY-models which serve to determine
nonperturbatively the temperature of phase decoherence where superconductivity
breaks down. We find the transition temperature T_c as a monotonous function of
the coupling strength and carrier density both in two and three dimensions, and
give analytic formulas for the merging of the temperature of phase decoherence
with the temperature of pair formation in the weak-coupling limit.Comment: Few typos corrected. Emails that were sent to the address
[email protected] in June and July 1999 were lost in a computer crash, so if
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