Vortex Structures in Ultra-Cold Atomic Gases

Verhelst, Nick; Tempere, J.

doi:10.5772/67121

Cited by 4 publications

(6 citation statements)

References 66 publications

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“…The corresponding studies in ultracold bosonic gases have focused on vortex-lattice oscillations (Tkachenko modes), quadrupolar modes of oscillations, rapid-rotation induced Landau quantization of states, etc. ; for reviews see [132,133]. These experimental studies find analogs in the physics of neutron stars, as will be explained in Section 5.…”

Section: Interface Between Nuclear Systems and Cold Atomic Gasesmentioning

confidence: 86%

Superfluidity in nuclear systems and neutron stars

2019

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Nuclear matter and finite nuclei exhibit the property of superfluidity by forming Cooper pairs. We review the microscopic theories and methods that are being employed to understand the basic properties of superfluid nuclear systems, with emphasis on the spatially extended matter encountered in neutron stars, supernova envelopes, and nuclear collisions. Our survey of quantum many-body methods includes techniques that employ Green functions, correlated basis functions, and Monte Carlo sampling of quantum states. With respect to empirical realizations of nucleonic and hadronic superfluids, this review is focused on progress that has been made toward quantitative understanding of their properties at the level of microscopic theories of pairing, with emphasis on the condensates that exist under conditions prevailing in neutron-star interiors. These include singlet S-wave pairing of neutrons in the inner crust, and, in the quantum fluid interior, singlet-S proton pairing and triplet coupled P -F -wave neutron pairing. Additionally, calculations of weak-interaction rates in neutron-star superfluids within the Green function formalism are examined in detail. We close with a discussion of quantum vortex states in nuclear systems and their dynamics in neutron-star superfluid interiors. PACS. 97.60.Jd Neutron stars -21.65.+f Nuclear matter -47.37.+q Hydrodynamic aspects of superfluidity; quantum fluids -67.85.+d Ultracold gases, trapped gases -74.25.Dw Superconductivity phase diagrams Contents arXiv:1802.00017v4 [nucl-th] 26 Sep 2019 emerge in the interaction part of the Hamiltonian when evaluating Eq. (5) in terms of Bogolyubov operators vanish. Such terms would account for fluctuations in the system, but are beyond the scope of the present mean-field treatment. 4 Note that the variation δ(E − µN )/δn p,↑ , with up and vp held constant, yields the quantity Ep, confirming its interpretation. Armen Sedrakian, John W. Clark: Superfluidity in nuclear systems and neutron stars 5

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Section: Interface Between Nuclear Systems and Cold Atomic Gasesmentioning

confidence: 86%

Superfluidity in nuclear systems and neutron stars

2019

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“…This is because the vortex core size of cold-atom gases in experimental studies is estimated to be of the order of healing length [33] (i.e. ∼ 100nm).…”

Section: The Black Hole Profile Of the Vortexmentioning

confidence: 99%

Echoes from the event horizon of a superfluid vortex

Güven

Demirkaya

2022

J. Phys.: Conf. Ser.

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A vortex formed in the superfluid state of a Bose-Einstein condensate may exhibit superradiance a la blackhole for radially propagating acoustic fluctuations. The analogy is usually based on the so-called draining bathtub model of the vortex, in which an event horizon and ergosphere emerges when the radial velocity of the superfluid exceeds the propagation speed of sound in the condensate. The acoustic fluctuations mimic a massless scalar field in the curved Lorentzian space-time of the vortex and are governed by the Klein-Gordon wave equation. One common main approximation is the constant background density of the superfluid even in the presence of the vortex. This sets a constant relativistic sound speed. However, the vortex state solution of the Gross-Pitaevskii equation clearly shows that both the density and the speed of sound vary radially near the vortex core, where the event horizon and thus the superradiance will take place. What changes would this complex interdependence bring to the formulation and to the outcomes of the superradiance based on constant density approximation? Here, we recount this question posed under the guidance of Prof. Tekin Dereli and present recent results. We show that the self-consistent density modifies the amplification dynamics near the event horizon significantly, thereby altering the temporal and spectral fingerprint of the superradiance of the vortex.

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“…The effective action functional (30) forms the basis of our EFT description of superfluid Fermi gases. The validity and limitations of the formalism are largely determined by the main assumption that the order parameter varies slowly in space and time, which corresponds to the condition that the pair field should vary over a spatial region much larger than the Cooper pair correlation length.…”

Section: The Effective Field Theorymentioning

confidence: 99%

“…As an application of the effective field theory, the general structure of a superfluid vortex will be numerically determined and compared with the commonly used variational hyperbolic tangent. A more detailed description on vortices in superfluids and their behavior can be found in [30].…”

Section: Application 2: the Vortex Structurementioning

confidence: 99%

“…For vortices in ultracold gases on the other hand, the vortex core size is of the order of micrometers [34], meaning that its structure becomes important 8 ; a simple cylindric hole will no longer capture the entire vortex physics. In order to provide a more detailed description, different variational models are available [9,30].…”

Section: A Variational Model For the Vortex Corementioning

confidence: 99%

See 1 more Smart Citation

An Effective Field Description for Fermionic Superfluids

Alphen¹,

Verhelst²,

Lombardi³

et al. 2018

Superfluids and Superconductors

Self Cite

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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.

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Vortex Structures in Ultra-Cold Atomic Gases

Cited by 4 publications

References 66 publications

Superfluidity in nuclear systems and neutron stars

Superfluidity in nuclear systems and neutron stars

Echoes from the event horizon of a superfluid vortex

An Effective Field Description for Fermionic Superfluids

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