English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

The theoretical description of the critical temperature Tc of a Fermisuperfluid dates back to the work by Gor'kov and Melik-Barkhudarov (GMB), whoaddressed it for a weakly-coupled (dilute) superfluid in the BCS(weak-coupling) limit of the BCS-BEC crossover. The point made by GMB was thatparticle-particle (pairing) excitations, which are responsible forsuperfluidity to occur below Tc, and particle-hole excitations, which give riseto screening also in a normal system, get effectively disentangled from eachother in the BCS limit, thus yielding a reduction by a factor 2.2 of the valueof Tc obtained when neglecting screening effects. Subsequent work on thistopic, aimed at extending the original GMB argument away from the BCS limitwith diagrammatic methods, has kept this disentangling between pairing andscreening throughout the BCS-BEC crossover, without realising that theconditions for it to be valid are soon violated away from the BCS limit. Here,we reconsider this problem from a more general perspective and argue thatpairing and screening are intrinsically entangled with each other along thewhole BCS-BEC crossover but for the BCS limit considered by GMB. We perform adetailed numerical calculation of the GMB diagrammatic contribution extended tothe whole BCS-BEC crossover, where the full wave-vector and frequencydependence occurring in the repeated in-medium two-particle scattering is dulytaken into account. Our numerical calculations are tested against analyticresults available in both the BCS and BEC limits, and the contribution of theGMB diagrammatic term to the scattering length of composite bosons in the BEClimit is highlighted. We calculate Tc throughout the BCS-BEC crossover and findthat it agrees quite well with Quantum Monte Carlo calculations andexperimental data available in the unitarity regime.

Entanglement between pairing and screening in the Gorkov-Melik-Barkhudarov correction to the critical temperature throughout the BCS-BEC crossover