The decay and collisions of dark solitons in superfluid Fermi gases

Scott, R. G.; Dalfovo, F.; Pitaevskiĭ, Lev P.; Stringari, S.; Fialko, O.; Liao, Rui; Brand, Joachim

doi:10.1088/1367-2630/14/2/023044

Cited by 23 publications

(41 citation statements)

References 46 publications

(100 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[21]). Subsequent studies found numerical solutions for moving solitons and investigated their properties [22][23][24], but have been confined to purely one-dimensional dynamics. Of relevance to this paper are also general results on solitonic properties outside the approximate BdG crossover theory based on Landau quasiparticle theory [22], scaling analysis in the unitarity limit [23], and hydrodynamics [25].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Snake instability of dark solitons in fermionic superfluids

et al. 2013

View full text Add to dashboard Cite

We present numerical calculations of the snake instability in a Fermi superfluid within the Bogoliubov-de Gennes theory of the BEC to BCS crossover using the random phase approximation complemented by time-dependent simulations. We examine the snaking behaviour across the crossover and quantify the timescale and lengthscale of the instability. While the dynamic shows extensive snaking before eventually producing vortices and sound on the BEC side of the crossover, the snaking dynamics is preempted by decay into sound due to pair breaking in the deep BCS regime. At the unitarity limit, hydrodynamic arguments allow us to link the rate of snaking to the experimentally observable ratio of inertial to physical mass of the soliton. In this limit we witness an unresolved discrepancy between our numerical estimates for the critical wavenumber of suppression of the snake instability and recent experimental observations with an ultra-cold Fermi gas.

show abstract

Section: Introductionmentioning

confidence: 99%

“…Previous papers [22][23][24] have described the stability and the excitation spectrum of travelling dark solitons in superfluid Fermi gases. Here we wish to perform an analysis of the decay modes of stationary solitons in the context of the BdG theory.…”

Section: Introductionmentioning

confidence: 99%

Snake instability of dark solitons in fermionic superfluids

et al. 2013

View full text Add to dashboard Cite

show abstract

“…However, the growth appears to remain linear, instead of exponential, for times t > τ 1 , which effect is possibly tied to the inhomogeneity of the transverse confinement. Indeed, within the local density approximation, each surface element of the soliton propagates at a fixed fraction of the local speed of sound, set by the current-phase relation [41,42]. This causes the bending of the soliton into a drumlike profile, whose amplitude increases at constant velocity.…”

mentioning

confidence: 99%

“…A natural extension of our work is to approach a regime where the snake instability is inhibited, e.g., via a strong confining potential in the radial direction. Future prospects are a measurement of the soliton's current-phase relation in the BEC-BCS crossover [41,42], the detection and manipulation of Andreev bound states trapped inside the soliton [3,4], and the creation of soliton trains in the presence of spin imbalance, which would realize one limit of Fulde-Ferrell-Larkin-Ovchinnikov states [43][44][45].…”

mentioning

confidence: 99%

Cascade of Solitonic Excitations in a Superfluid Fermi gas: From Planar Solitons to Vortex Rings and Lines

et al. 2016

View full text Add to dashboard Cite

We follow the time evolution of a superfluid Fermi gas of resonantly interacting 6 Li atoms after a phase imprint. Via tomographic imaging, we observe the formation of a planar dark soliton, its subsequent snaking, and its decay into a vortex ring, which, in turn, breaks to finally leave behind a single solitonic vortex. In intermediate stages, we find evidence for an exotic structure resembling the Φ soliton, a combination of a vortex ring and a vortex line. Direct imaging of the nodal surface reveals its undulation dynamics and its decay via the puncture of the initial soliton plane. The observed evolution of the nodal surface represents dynamics beyond superfluid hydrodynamics, calling for a microscopic description of unitary fermionic superfluids out of equilibrium.

show abstract

“…They appear in many areas of science, such as water waves, nonlinear optics, biophysics and plasma and particle physics [1], and more recently in Bose-Einstein condensate [2][3][4]. Since the first observation of the crossover from a Bardeen-Cooper-Schrieffer(BCS) superfluid to a Bose-Einstein condensation(BEC) in ultracold fermionic atomic gases [5][6][7][8][9], understanding formation, dynamics and stability of solitons in a strongly interacting fermionic system has been attracted great attention [10,11], and explored theoretically [12][13][14][15][16][17][18][19].…”

Section: Introductionmentioning

confidence: 99%

Dark-soliton dynamics and snake instability in superfluid Fermi gases trapped by an anisotropic harmonic potential

Wen

Zhao

2013

Phys. Rev. A

View full text Add to dashboard Cite

We present an investigation of generation, dynamics and stability of dark solitons in anisotropic Fermi gases for a range of particle numbers and trap aspect ratios within the framework of the order-parameter equation. We calculate the periods of dark solitons oscillating in a trap, and find a good agreement with the results based on the Bogoliubov-de Gennes equations. By studying the stability of initially off-center dark solitons under various tight transverse confinements in the unitarity limit, we not only give the criterion of dynamical stability, but also find that the soliton and a hybrid of solitons and vortex rings can be characterized by different oscillation period. The stability criterion is not fulfilled by the parameters of the recent experiment [Nature 499, 426 (2013)]. Therefore, instead of a very slow oscillation as observed experimentally, we find that the created dark soliton undergoes a transverse snake instability with collapsing into vortex rings, which propagate in soliton-like manner with a nearly two times larger period.

show abstract

The decay and collisions of dark solitons in superfluid Fermi gases

Cited by 23 publications

References 46 publications

Snake instability of dark solitons in fermionic superfluids

Snake instability of dark solitons in fermionic superfluids

Cascade of Solitonic Excitations in a Superfluid Fermi gas: From Planar Solitons to Vortex Rings and Lines

Dark-soliton dynamics and snake instability in superfluid Fermi gases trapped by an anisotropic harmonic potential

Contact Info

Product

Resources

About