Verification of an analytic fit for the vortex core profile in superfluid Fermi gases

Verhelst, Nick; Klimin, S. N.; Tempere, J.

doi:10.1016/j.physc.2016.06.020

Cited by 8 publications

(13 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A similar expression was derived in the context of the EFT for the width of a vortex core in Ref. [33]. A more extensive study on the healing length of a fermionic superfluid across the BEC-BCS crossover can be found in Ref.…”

Section: Resultsmentioning

confidence: 72%

Crossover between snake instability and Josephson instability of dark solitons in superfluid Fermi gases

2019

View full text Add to dashboard Cite

Dark solitons in superfluid Bose gases decay through the snake instability mechanism, unless they are strongly confined. Recent experiments in superfluid Fermi gases have also interpreted soliton decay via this mechanism. However, we show using both an effective field numerical simulation and a perturbative analysis that there is a qualitative difference between soliton decay in the BEC-and BCS-regimes. On the BEC-side of the interaction domain, the characteristic snaking deformations are induced by fluctuations of the amplitude of the order parameter, while on the BCS-side, fluctuations of the phase destroy the soliton core through the formation of local Josephson currents. The latter mechanism is qualitatively different from the snaking instability and this difference should be experimentally detectable. * wout.vanalphen@uantwerpen.be arXiv:1901.10751v1 [cond-mat.quant-gas]

show abstract

Section: Resultsmentioning

confidence: 72%

Crossover between snake instability and Josephson instability of dark solitons in superfluid Fermi gases

2019

View full text Add to dashboard Cite

show abstract

“…In this Appendix we show that, in the BEC (strong-coupling) limit of the BCS-BEC crossover, whereby the fermionic BdG equations reduce to the bosonic Gross-Pitaevskii (GP) equation for the composite bosons that form in this limit [16], the (ρ −2 ) long-range behavior of the condensate wave function Φ(r) = m 2 a F 8π ∆(r) can be determined by simple analytic considerations. Although this result has already been reported for a vortex filament in an almost ideal Bose gas described at low temperature by the GP equation [29], the reason to briefly discuss it here is that its relevance for a vortex in a fermionic superfluid described by the BdG equations has passed essentially unnoticed in the literature [1,5,18].…”

Section: Appendix A: Internal Structure Of a Vortexmentioning

confidence: 69%

Bound states in a superfluid vortex: A detailed study along the BCS-BEC crossover

2019

View full text Add to dashboard Cite

The bound states that can occur in a superfluid vortex have recently called for attention owing to the capability of detecting them experimentally. However, a detailed theoretical account for the presence of these vortex bound states is still lacking, for all temperatures in the superfluid phase and couplings along the BCS-BEC crossover. Here, we fill this gap and present a systematic theoretical study based on the Bogoliubov-de Gennes equations for the bound states that occur over the two characteristic (inner and outer) spatial ranges in which the extension of a superfluid vortex can be partitioned. It is found that the total number of bound states decreases from the BCS (weak-coupling) side of the crossover toward the intermediate-coupling region where they are still present, whereas the bound states disappear upon entering the BEC (strong-coupling) side. A scaling relation is also obtained that connects the number of bound states in the inner spatial range of the vortex to the depth and width of the vortex itself. A criterion is finally provided in terms of the local density of states, to distinguish where a given fermionic superfluid is located in the coupling-temperature phase diagram of the BCS-BEC crossover.arXiv:1904.03883v1 [cond-mat.supr-con]

show abstract

“…The numerical method that was used in order to determine the exact vortex structure for a given set of parameters β; a s ; ζ ÀÁ is discussed in full detail in [38]. In a nutshell, this method comes down to making a discretized version of the vortex structure: f 1 ; f 2 ; …; f N ÈÉ , where f 1 ¼ 0 and f N ¼ 1 due to the boundary conditions.…”

Section: Comparison To the Exact (Numerical) Solutionmentioning

confidence: 99%

An Effective Field Description for Fermionic Superfluids

Alphen¹,

Verhelst²,

Lombardi³

et al. 2018

Superfluids and Superconductors

Self Cite

View full text Add to dashboard Cite

In this chapter, we present the details of the derivation of an effective field theory (EFT) for a Fermi gas of neutral dilute atoms and apply it to study the structure of both vortices and solitons in superfluid Fermi gases throughout the BEC-BCS crossover. One of the merits of the effective field theory is that, for both applications, it can provide some form of analytical results. For one-dimensional solitons, the entire structure can be determined analytically, allowing for an easy analysis of soliton properties and dynamics across the BEC-BCS interaction domain. For vortices on the other hand, a variational model has to be proposed. The variational parameter can be determined analytically using the EFT, allowing to also study the vortex structure (variationally) throughout the BEC-BCS crossover.

show abstract

Verification of an analytic fit for the vortex core profile in superfluid Fermi gases

Cited by 8 publications

References 30 publications

Crossover between snake instability and Josephson instability of dark solitons in superfluid Fermi gases

Crossover between snake instability and Josephson instability of dark solitons in superfluid Fermi gases

Bound states in a superfluid vortex: A detailed study along the BCS-BEC crossover

An Effective Field Description for Fermionic Superfluids

Contact Info

Product

Resources

About