In the limit of weak coupling, [itex]G\overline{ρ}<<1[/itex], the BCS pairing gap equation gives that [itex]Δ \propto exp(-1/G\overline{ρ})[/itex]. [itex]\overline{ρ}[/itex] is the level density.This cannot be developed as a power series in the interaction strength G. Does this imply that there is a phase transition between a superfluid and a normal fluid state? If so, how exactly?(adsbygoogle = window.adsbygoogle || []).push({});

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# Pairing gap equation weak coupling

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