Structure of vortex shedding past potential barriers moving in a Bose-Einstein condensate

Миронов, В. А.; Смирнов, А. И.; Smirnov, L. A.

doi:10.1134/s1063776110050195

Cited by 35 publications

(26 citation statements)

References 26 publications

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“…Such observations have triggered a clear interest towards their possible hydrodynamic formation and stability. In particular, dark solitons are known to be unstable with respect to transverse perturbations [71,72] and to eventually decay into other more stable structures [73][74][75]. [43] In this paragraph, we follow on the previous experiments on turbulence, using the same homodyne detection system, with the same sample, however, this time, the defect is an engineered defect (mesa) that allows a better control on the experimental parameters [76].…”

Section: Dark Solitons and Vortex Streetsmentioning

confidence: 99%

Dynamics of Vortices and Dark Solitons in Polariton Superfluids

Deveaud

Nardin

Léger

2013

Physics of Quantum Fluids

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In this chapter we describe some observations linked with turbulence in quantum fluids of polaritons. We imprint a given velocity and density to the polariton fluid by using an appropriate pulse intensity and wavevector. The flow is then perturbed by a natural defect or more interestingly, by engineered traps with a well defined potential change. The flow of the fluid is measured in a time resolved fashion through the use of homodyne detection. Both the intensity and the phase of the fluid can then be retrieved with a picosecond resolution. This allows observing the nucleation of quantized vortices, with the appropriate 2π phase shift around the core, or the growth of dark solitons in the wake of the obstacle. The dark solitons are observed to decay into vortex streets. Our results are compared to dynamical solutions of the Gross-Pitaevskii equation and a very good agreement is obtained allowing us to hold good confidence in our interpretation.Hydrodynamics is an important field of physics with a wide range of well established results, and still some parts of the field under active investigation because of the importance of hydrodynamics, and in particular of hydrodynamical instabilities for major practical applications. Hydrodynamical instabilities have been studied experimentally at the beginning of the twentieth century with in particular the seminal papers of Bénard [1]. Such instabilities include many different possible cases, with in particular the convective Bénard-Rayleigh flows and Bénard-Von Kármán streets [2]. The flow around an obstacle is characterized, in conventional fluids, by the Reynolds number, a dimensionless parameter given by R e = vR/υ where v represents the fluid velocity and υ its dynamical viscosity, R being the diameter of the obstacle. Upon increasing the Reynolds number, either through the size of the obstacle or the speed of the fluid, the following phenomenology is successively observed: laminar flow, stationary vortices, Bénard-Von Kármán streets of moving vortices and eventually fully turbulent regime [3]. Such phenomena are observed in various configurations and with a wide variety of classical fluids.B. Deveaud (B) · G. Nardin · G. Grosso · Y. Léger Ecole Polytechnique Fédérale de Lausanne,

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Section: Dark Solitons and Vortex Streetsmentioning

confidence: 99%

Dynamics of Vortices and Dark Solitons in Polariton Superfluids

Deveaud

Nardin

Léger

2013

Physics of Quantum Fluids

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“…[21], in which a steady state was created by a continuous wave pumping, our pulsed experiments allow us to retrieve the dynamics of the polariton fluid and thus to reconstruct the temporal behavior of dark solitons. Time and phase resolution consents to observe the formation of vortex streets arising from the unstable nature of solitons and to quantitatively access the stability conditions.It is well known that dark solitons are unstable with respect to transverse perturbations [22,23] and that they eventually decay into other more stable structures [24][25][26]. The driven dissipative nature of polaritons results in the exploration of different hydrodynamic regimes enriching the achievable features of polariton solitons.…”

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confidence: 99%

“…It is well known that dark solitons are unstable with respect to transverse perturbations [22,23] and that they eventually decay into other more stable structures [24][25][26]. The driven dissipative nature of polaritons results in the exploration of different hydrodynamic regimes enriching the achievable features of polariton solitons.…”

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confidence: 99%

Soliton Instabilities and Vortex Street Formation in a Polariton Quantum Fluid

et al. 2011

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Exciton polaritons have been shown to be an optimal system in order to investigate the properties of bosonic quantum fluids. We report here on the observation of dark solitons in the wake of engineered circular obstacles and their decay into streets of quantized vortices. Our experiments provide a timeresolved access to the polariton phase and density, which allows for a quantitative study of instabilities of freely evolving polaritons. The decay of solitons is quantified and identified as an effect of disorderinduced transverse perturbations in the dissipative polariton gas. DOI: 10.1103/PhysRevLett.107.245301 PACS numbers: 67.10.Jn, 03.75.Lm, 71.36.+c, 78.67.Àn Perturbations of quantum fluids can lead to the creation of solitary waves called solitons resulting from the compensation between dispersion and particle interaction. In the particular case of repulsive interaction, dark solitons are created. These density depressions move in the fluid while keeping a constant shape and they are characterized by a phase jump across the density minimum. Since the first theoretical prediction [1], dark solitons have been studied and then observed in a variety of systems such as nonlinear lattices [2], thin magnetic films [3], and complex plasma [4]. They have attracted considerable interest especially in the field of nonlinear optics [5], because of their consequent use in communication devices (i.e., optical fibers [6]), and in atomic Bose-Einstein condensation (BEC) [7]. As quantized vortices [8][9][10], dark solitons are BEC excitations, which arise spontaneously upon the phase transition. As such, they are clear evidences for the onset of a quantum behavior and powerful tools to understand BEC instabilities. Controlling these instabilities is of crucial importance for the development of optoelectronic devices based on quantum fluids in which stable regimes and structures are required. Dark solitons are considered as the dispersive and nonlinear analog of shock waves of supersonic motion [11]. The creation of solitons by phase imprinting in BEC has been reported [12,13], triggering a growing interest in their hydrodynamic formation and stability of solitons.In this Letter we report on the observation of hydrodynamic oblique dark solitons in a 2D polariton fluid and the formation of quantized vortex streets. Polaritons are bosonic quasiparticles arising from the strong coupling between quantum well excitons and photons in semiconductor microcavities. Because of their small effective mass and their strong nonlinearity, they have turned out to be an optimal system in order to investigate the properties of a bosonic quantum fluid. Polaritons can undergo BEC [14] and, by virtue of their nonequilibrium nature, they are accompanied with the spontaneous appearance of quantized vortices [15]. With the demonstration of polariton superfluidity [16,17] much effort has been performed to better understand the nature of different turbulences arising from the breakdown of this fascinating state of matter. Recently, the hydrodynam...

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“…The nature of the medium perturbation and the properties of the induced non-equilibrium interaction are defined by the properties of the medium (e.g., by its nonlinearity) and the mechanism of energy losses. The perturbation can lead to generation of vortices, Cherenkov radiation, or local phase transitions (some more effect can be found in hydrodynamics [1][2][3][4][5][6], optics [7], plasma physics [8][9][10][11][12][13], quantum liquids and Bose condensates [14][15][16][17][18][19][20]). …”

Section: Introductionmentioning

confidence: 99%

Effects of gas interparticle interaction on dissipative wake-mediated forces

Kliushnychenko

Lukyanets

2017

Phys. Rev. E

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The effect of concentration-dependent switching of the non-equilibrium depletion interaction between obstacles in a gas flow of interacting Brownian particles is presented. When increasing bath fraction exceeds half-filling, the wake-mediated interaction between obstacles switches from effective attraction to repulsion or vice-versa, depending on the mutual alignment of obstacles with respect to the gas flow. It is shown that for an ensemble of small and widely separated obstacles the dissipative interaction takes the form of induced dipole-dipole interaction governed by an anisotropic screened Coulomb-like potential. This allows one to give a qualitative picture of the interaction between obstacles and explain switching effect as a result of changes of anisotropy direction. The non-linear blockade effect is shown to be essential near closely located obstacles, that manifests itself in additional screening of the gas flow and generation of a pronounced step-like profile of gas density distribution. It is established that behavior of the magnitude of dissipative effective interaction is, generally, non-monotonic in relation to both the bath fraction and the external driving field. It has characteristic peaks corresponding to the situation when the common density "coat" formed around the obstacles is most pronounced. The possibility of the dissipative pairing effect is briefly discussed. All the results are obtained within the classical lattice-gas model.

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Structure of vortex shedding past potential barriers moving in a Bose-Einstein condensate

Cited by 35 publications

References 26 publications

Dynamics of Vortices and Dark Solitons in Polariton Superfluids

Dynamics of Vortices and Dark Solitons in Polariton Superfluids

Soliton Instabilities and Vortex Street Formation in a Polariton Quantum Fluid

Effects of gas interparticle interaction on dissipative wake-mediated forces

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