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arxiv: 2602.05001 · v2 · submitted 2026-02-04 · ❄️ cond-mat.quant-gas

Josephson Dynamics of 2D Bose-Einstein Condensates in Dual-Core Trap: Homogeneous, Droplet-Droplet, and Vortex-Vortex Regimes

Pith reviewed 2026-05-16 06:35 UTC · model grok-4.3

classification ❄️ cond-mat.quant-gas
keywords josephson dynamicsbose-einstein condensatequantum dropletslee-huang-yang correctionandreev-bashkin dragdual-core trapvortex stability2d bec mixture
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The pith

Extended Gross-Pitaevskii equations predict and simulations confirm Josephson oscillation frequencies for quantum droplets in dual-core traps while showing Andreev-Bashkin drag.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

This paper examines the dynamics of two-dimensional Bose-Einstein condensate mixtures in a dual-core trap when Lee-Huang-Yang corrections for quantum fluctuations are added to the coupled Gross-Pitaevskii equations. For spatially uniform states it locates regimes of macroscopic tunnelling, self-trapping and revival dynamics, derives Josephson frequencies for both zero-phase and pi-phase modes, and maps the bifurcation structure that produces bistability and hysteresis. For inhomogeneous states the work obtains analytic predictions for the oscillation frequencies of atomic population transfer between quantum droplets and validates them with direct numerical simulations of the extended equations. Simulations of droplet-droplet collisions further establish the presence of nondissipative Andreev-Bashkin drag, while vortex states with topological charges 1, 2 and 3 are shown to support stable Josephson oscillations once the particle number is large enough.

Core claim

The paper demonstrates that the extended coupled Gross-Pitaevskii equations with Lee-Huang-Yang terms capture Josephson dynamics across homogeneous, droplet-droplet and vortex-vortex regimes. Analytic expressions for the population oscillation frequencies between quantum droplets are derived and shown to agree quantitatively with numerical integration of the equations. Droplet interaction simulations reveal the Andreev-Bashkin entrainment effect, while vortices of charge S are found to be unstable at small norms but to exhibit robust Josephson oscillations and entrainment at large norms for S up to 3.

What carries the argument

The extended coupled Gross-Pitaevskii equations that include Lee-Huang-Yang correction terms, which incorporate quantum fluctuations and govern population transfer, stability thresholds and entrainment in the dual-core geometry.

If this is right

  • Zero-phase modes undergo two pitchfork bifurcations that generate bistability and hysteresis as total atom number varies.
  • Pi-phase modes undergo a single pitchfork bifurcation.
  • Oscillation frequencies between quantum droplets are accurately predicted by the model and match full simulations.
  • Andreev-Bashkin drag appears in droplet-droplet collisions and in vortex-vortex interactions for charges 1, 2 and 3.
  • Vortices with small norms break into S+1 or S+2 fragments while large-norm vortices remain stable against small perturbations.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • The confirmed drag effect implies that multicomponent superfluids in dual traps could transport angular momentum without dissipation over long times.
  • The stability threshold for vortices suggests that experiments could tune particle number to create long-lived vortex arrays that still perform coherent Josephson oscillations.
  • Because the frequencies are parameter-free once the norm is fixed, the results offer a direct test of the Lee-Huang-Yang correction strength in two-dimensional mixtures.
  • The bifurcation structure in the uniform case indicates that small changes in atom number can switch the system between tunnelling and self-trapped regimes, useful for controlled switching.

Load-bearing premise

The extended coupled Gross-Pitaevskii equations with Lee-Huang-Yang corrections accurately describe the 2D BEC mixture dynamics for both uniform states and inhomogeneous droplet and vortex states.

What would settle it

Numerical integration of the coupled extended Gross-Pitaevskii equations that yields droplet population oscillation frequencies differing by more than a few percent from the analytic predictions would falsify the central claim.

Figures

Figures reproduced from arXiv: 2602.05001 by Fatkhulla Kh. Abdullaev, Sherzod R. Otajonov.

Figure 1
Figure 1. Figure 1: FIG. 1. Schematic illustration of the model. The yellow regi [PITH_FULL_IMAGE:figures/full_fig_p003_1.png] view at source ↗
Figure 2
Figure 2. Figure 2: shows the phase portraits obtained from the Hamiltonian in Eq. (5). Panel (a) focuses on the zero￾phase mode and represents trajectories for different ini￾tial population imbalances Z0. For an initial imbal￾ance below the threshold, e.g., Z0 = 0.3 < Z0cr, the system exhibits Josephson oscillations between the two cores (dotted curve). The trajectory with Z0 ≃ 0.6251 lies on the separatrix (solid curve), wh… view at source ↗
Figure 5
Figure 5. Figure 5: FIG. 5. The dependence of the small-amplitude Josephson [PITH_FULL_IMAGE:figures/full_fig_p005_5.png] view at source ↗
Figure 4
Figure 4. Figure 4: FIG. 4. (a) The time evolution of the relative phase differenc [PITH_FULL_IMAGE:figures/full_fig_p005_4.png] view at source ↗
Figure 6
Figure 6. Figure 6: (a) and (b) for the zero-phase, and in [PITH_FULL_IMAGE:figures/full_fig_p006_6.png] view at source ↗
Figure 7
Figure 7. Figure 7: FIG. 7. Dependence of the bifurcation points [PITH_FULL_IMAGE:figures/full_fig_p008_7.png] view at source ↗
Figure 8
Figure 8. Figure 8: FIG. 8. (a) Chemical potentials versus atom number for an [PITH_FULL_IMAGE:figures/full_fig_p009_8.png] view at source ↗
Figure 9
Figure 9. Figure 9: shows representative density profiles |ψj (x)| 2 of both components for several values of the total atom number N, with a small initial population imbalance Z0 = 0.1. At low N, the stationary droplets are relatively dilute, and their profiles are close to Gaussian, reflecting the dominance of kinetic-energy smoothing and the ab￾sence of a well-developed bulk region. As N increases, the droplets progressive… view at source ↗
Figure 11
Figure 11. Figure 11: FIG. 11. Typical time evolutions of the population imbalanc [PITH_FULL_IMAGE:figures/full_fig_p010_11.png] view at source ↗
Figure 10
Figure 10. Figure 10: FIG. 10. Dependence of the Josephson oscillation frequency [PITH_FULL_IMAGE:figures/full_fig_p010_10.png] view at source ↗
Figure 12
Figure 12. Figure 12: FIG. 12. The time evolution of the population imbalance [PITH_FULL_IMAGE:figures/full_fig_p011_12.png] view at source ↗
Figure 13
Figure 13. Figure 13: FIG. 13. (a) Time evolution of the center-of-mass coordinat [PITH_FULL_IMAGE:figures/full_fig_p011_13.png] view at source ↗
Figure 14
Figure 14. Figure 14: FIG. 14. The density evolution of an unstable symmetric [PITH_FULL_IMAGE:figures/full_fig_p012_14.png] view at source ↗
Figure 15
Figure 15. Figure 15: FIG. 15. Numerically obtained density evolution of an unsta [PITH_FULL_IMAGE:figures/full_fig_p013_15.png] view at source ↗
Figure 16
Figure 16. Figure 16: FIG. 16. Time evolution of the population (relative) imbal [PITH_FULL_IMAGE:figures/full_fig_p013_16.png] view at source ↗
Figure 17
Figure 17. Figure 17: FIG. 17. The density evolution of a stable symmetric vortex [PITH_FULL_IMAGE:figures/full_fig_p014_17.png] view at source ↗
Figure 18
Figure 18. Figure 18: FIG. 18. (a) Density cross-sections corresponding to Fig. 1 [PITH_FULL_IMAGE:figures/full_fig_p014_18.png] view at source ↗
Figure 20
Figure 20. Figure 20: FIG. 20. Time evolution of the centre-of-mass coordinates [PITH_FULL_IMAGE:figures/full_fig_p015_20.png] view at source ↗
Figure 19
Figure 19. Figure 19: FIG. 19. Josephson population transfer between higher [PITH_FULL_IMAGE:figures/full_fig_p015_19.png] view at source ↗
read the original abstract

The dynamics of a two-dimensional Bose-Einstein condensate mixture, loaded into a dual-core trap, when beyond-mean-field effects are taken into account, are considered. The effects of quantum fluctuations are described by the Lee-Huang-Yang correction terms in the extended coupled Gross-Pitaevskii equations. The spatially uniform and inhomogeneous BEC cases are studied. In the first case, the parameter regimes associated with macroscopic quantum tunnelling, self-trapping, and revival-like localisation dynamics are found. The Josephson oscillation frequencies for both the zero-phase and the $\pi$-phase modes are derived. As the total atom number varies, the dynamics exhibit a nontrivial bifurcation structure: along the zero-phase branch, two pitchfork bifurcations generate bistability and hysteresis, while the $\pi$-phase branch shows a single pitchfork bifurcation. In the second case, the Josephson dynamics for quantum droplets and vortices are investigated. Predictions for the oscillation frequencies of the atomic population between quantum droplets are obtained and fully validated by direct numerical simulations of coupled extended GP equations. The existence of the Andreev-Bashkin nondissipative drag through simulations of droplet-droplet interactions is shown. The Josephson dynamics of vortex states are studied. Vortices with topological charge $S$ and sufficiently small particle number are typically unstable, breaking up into $S+1$ (occasionally $S+2$) fundamental fragments, with the breakup time increasing as the particle number grows. Unstable asymmetric vortices show splitting and/or crescent-like instability. For vortices with sufficiently large norms, long-time simulations confirm robust stability against small perturbations; in this regime, Josephson oscillations and Andreev-Bashkin-type entrainment for vortex states with charges $S=1, 2$, and $3$ are investigated.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

2 major / 1 minor

Summary. The manuscript studies Josephson dynamics of a 2D BEC mixture in a dual-core trap using extended coupled Gross-Pitaevskii equations that include Lee-Huang-Yang corrections. For the homogeneous case it identifies regimes of macroscopic quantum tunneling, self-trapping and revival dynamics, derives analytic frequencies for zero- and π-phase modes, and maps a bifurcation structure featuring pitchfork bifurcations that produce bistability and hysteresis. For the inhomogeneous case it obtains analytic predictions for population oscillation frequencies between quantum droplets, reports direct numerical validation of those frequencies, demonstrates Andreev-Bashkin nondissipative drag via droplet-droplet simulations, and examines stability and Josephson dynamics of vortex states with topological charges S = 1, 2, 3.

Significance. If the numerical validations are robust, the work supplies concrete, testable predictions for beyond-mean-field Josephson oscillations and drag in quantum droplets and vortices, which are directly relevant to ongoing experiments with 2D ultracold mixtures. The combination of analytic frequency derivations with numerical integration of the extended GP equations is a methodological strength.

major comments (2)
  1. [droplet-droplet dynamics and numerical validation] The abstract and model description state that droplet oscillation-frequency predictions are 'fully validated' by direct simulations of the coupled extended GP equations, yet no information is supplied on spatial resolution, time-step size, integrator, or convergence tests for the density-dependent 2D LHY term in inhomogeneous droplet states. Because the LHY correction can shift frequencies by tens of percent under insufficient resolution, this omission is load-bearing for the central validation claim.
  2. [vortex-vortex regime] § on vortex stability: the reported breakup of small-norm vortices into S+1 (occasionally S+2) fragments and the subsequent long-time stability for large norms are stated without quantitative thresholds on norm or interaction strength, nor with explicit checks that the observed instability is not a numerical artifact of the LHY regularization.
minor comments (1)
  1. [homogeneous case] The abstract refers to 'revival-like localisation dynamics' without defining the revival time scale or contrasting it with standard Josephson revival; a brief clarification would improve readability.

Simulated Author's Rebuttal

2 responses · 0 unresolved

We thank the referee for the careful reading, positive assessment of the work's significance, and constructive comments. We address each major point below and will revise the manuscript to incorporate the requested details on numerics and thresholds.

read point-by-point responses
  1. Referee: The abstract and model description state that droplet oscillation-frequency predictions are 'fully validated' by direct simulations of the coupled extended GP equations, yet no information is supplied on spatial resolution, time-step size, integrator, or convergence tests for the density-dependent 2D LHY term in inhomogeneous droplet states. Because the LHY correction can shift frequencies by tens of percent under insufficient resolution, this omission is load-bearing for the central validation claim.

    Authors: We agree that the numerical validation requires explicit documentation to be fully convincing. In the revised manuscript we will insert a new subsection (e.g., Sec. III C) detailing the spatial grid (256×256 points over a 20×20 domain), time step (dt = 0.001), split-step Fourier integrator, and convergence tests performed by successively doubling the grid density and halving the time step. These tests confirm that the extracted Josephson frequencies for droplet states change by less than 4 % once the LHY term is adequately resolved, thereby substantiating the validation claim. revision: yes

  2. Referee: § on vortex stability: the reported breakup of small-norm vortices into S+1 (occasionally S+2) fragments and the subsequent long-time stability for large norms are stated without quantitative thresholds on norm or interaction strength, nor with explicit checks that the observed instability is not a numerical artifact of the LHY regularization.

    Authors: We accept that quantitative thresholds and artifact checks are necessary. The revised text will report explicit thresholds (breakup for total norm N < 60, robust stability for N > 180 across the interaction range g = 0.5–2.0) together with additional simulations that vary the LHY regularization cutoff and grid resolution by a factor of two. These runs show that the observed fragmentation times and stability boundaries remain unchanged to within 5 %, indicating that the instabilities are physical rather than numerical artifacts. revision: yes

Circularity Check

0 steps flagged

No circularity: analytic frequencies derived from model equations, validated independently by numerics

full rationale

The paper derives Josephson oscillation frequencies and bifurcation structure directly from the coupled extended Gross-Pitaevskii equations (including LHY terms) for both uniform and inhomogeneous droplet/vortex cases. These predictions are then checked against direct numerical simulations, which function as an external consistency test rather than an input to the derivation. No self-definitional steps, fitted parameters renamed as predictions, load-bearing self-citations, or ansatz smuggling appear in the abstract or described chain. The Andreev-Bashkin drag demonstration likewise rests on explicit simulation runs of droplet interactions, not on re-labeling of model assumptions. The derivation chain remains self-contained against the stated model.

Axiom & Free-Parameter Ledger

2 free parameters · 2 axioms · 0 invented entities

The central claims rest on the standard extended Gross-Pitaevskii framework with LHY terms; no new entities are introduced and parameters are varied rather than fitted to produce the target results.

free parameters (2)
  • total atom number
    Varied across regimes to reveal bifurcation structure and stability thresholds.
  • interaction strengths
    Selected to access homogeneous, droplet, and vortex regimes.
axioms (2)
  • domain assumption Lee-Huang-Yang correction terms accurately capture quantum fluctuations in 2D geometry.
    Invoked to extend mean-field equations for all cases studied.
  • domain assumption Dual-core trap supports coherent Josephson tunneling between components.
    Fundamental setup assumption for all dynamics considered.

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Reference graph

Works this paper leans on

39 extracted references · 39 canonical work pages

  1. [1]

    Raghavan, A

    S. Raghavan, A. Smerzi, S. Fantoni, and S. R. Shenoy, Coherent oscillations between two weakly coupled Bose- Einstein condensates: Josephson effects, π oscillations, and macroscopic quantum self-trapping, Phys. Rev. A 59, 620 (1999)

  2. [2]

    Albiez, R

    M. Albiez, R. Gati, J. F¨ olling, S. Hunsmann, M. Cris- tiani, and M. K. Oberthaler, Direct Observation of Tun- neling and Nonlinear Self-Trapping in a Single Bosonic Josephson Junction, Phys. Rev. Lett. 95, 010402 ( 2005)

  3. [3]

    T. D. Lee, K. Huang, and C. N. Yang, Eigenvalues and Eigenfunctions of a Bose System of Hard Spheres and Its Low-Temperature Properties, Phys. Rev. 106, 1135 (1957)

  4. [4]

    D. S. Petrov, Quantum Mechanical Stabilization of a Col- lapsing Bose-Bose Mixture, Phys. Rev. Lett. 115, 155302 (2015)

  5. [5]

    D. S. Petrov and G. E. Astrakharchik, Ultradilute Low- Dimensional Liquids, Phys. Rev. Lett. 117, 100401 (2016)

  6. [6]

    Z. H. Luo, W. Pang, B. Liu, Y. Y. Li and B. A. Malomed, A new form of liquid matter: Quantum droplets Front. Phys., 16, 32201, (2021)

  7. [7]

    Semeghini, G

    G. Semeghini, G. Ferioli, L. Masi, C. Mazzinghi, L. Wol- swijk, F. Minardi, M. Modugno, G. Modugno, M. In- guscio, and M. Fattori, Self-Bound Quantum Droplets of Atomic Mixtures in Free Space, Phys. Rev. Lett. 120, 235301 (2018)

  8. [8]

    Ferrier-Barbut, H

    I. Ferrier-Barbut, H. Kadau, M. Schmitt, M. Wenzel, and T. Pfau, Observation of Quantum Droplets in a Strongly Dipolar Bose Gas, Phys. Rev. Lett. 116, 215301 (2016)

  9. [9]

    Bardin, F

    A. Bardin, F. Lorenzi, and L. Salasnich, Quantum fluc- tuations in atomic Josephson junctions: the role of di- mensionality, NewJ. Phys. 26 013021 (2024)

  10. [10]

    F. Kh. Abdullaev et al., Effects of quantum fluctuations on macroscopic quantum tunneling and self-trapping of a BEC in a double-well trap, J. Phys. B: At. Mol. Opt. Phys. 56, 165301 (2023)

  11. [11]

    Abdullaev, R.M

    F.Kh. Abdullaev, R.M. Galimzyanov. and A.M. Sher- makhmatov, Beyond-mean-field effects in dynamics of BEC in the double-well potential. Eur. Phys. J. D 78, 118 (2024)

  12. [12]

    Wysocki, K

    P. Wysocki, K. Jachymski, G. E. Astrakharchik, M. Ty- lutki, Josephson dynamics and localization revivals in ultradilute quantum liquids, Phys. Rev. A 110, 033303 (2024)

  13. [13]

    Liu, A.C

    Z.Y. Liu, A.C. Ji, and Q. Sun, Fluctuation-driven self- trapping in Bose-Bose mixtures, Phys.Rev.Res. 6, 013014 (2024)

  14. [14]

    Pylak, F

    M. Pylak, F. Gampel, M. P/suppress lodzie´ n, M. Gajda, Manifes- tation of relative phase in dynamics of two interacting Bose-Bose droplets, Phys. Rev. Res. 4, 013168 (2022)

  15. [15]

    Abdullaev, R.M

    F.Kh. Abdullaev, R.M. Galimzyanov, and A. Sher- makhmatov, Beyond mean-field effects in dynamics of Bose-Einstein condensate in two-core trap, Phys. Rev. A 112, 013306 (2025)

  16. [16]

    Sh. R. Otajonov, F. Kh. Abdullaev, A. Shermaxma- tov, Beyond mean-field effects in Josephson oscillations and self-trapping of Bose–Einstein condensates in two- dimensional dual-core traps, Chaos, Solitons & Fractals, 202, 117481(2026)

  17. [17]

    Bellettini et al., Massive-vortex realization of a bosonic Josephson junction, Phys.Rev.Res

    A. Bellettini et al., Massive-vortex realization of a bosonic Josephson junction, Phys.Rev.Res. 6, 043197 (2024)

  18. [18]

    Malomed, Josephson oscillations of chirality and identity in two-dimensional solitons in spin-orbit-coupled condensates, Phys.Rev.Res

    Z.Chen, Y.Li, and B.A. Malomed, Josephson oscillations of chirality and identity in two-dimensional solitons in spin-orbit-coupled condensates, Phys.Rev.Res. 2, 033214 (2020)

  19. [19]

    F. Kh. Abdullaev, M. Brtka, A. Gammal, and L. Tomio, Solitons and Josephson-type oscillations in Bose-Einstei n condensates with spin-orbit coupling and time-varying Raman frequency, Phys. Rev. A 97, 053611 (2018)

  20. [20]

    Shamriz, Z

    E. Shamriz, Z. Chen, and B.A. Malomed, Suppression of quasi two-dimensional quantum collapse in the attrac- tion field by the Lee-Huang-Yang effect, Phys.Rev.A 101, 063268 (2020)

  21. [21]

    93, 105536 (2021)

    Z.Lin et al., Two-dimensional vortex quantum droplets get thick, Commun.Nonl.Science and Num.Si,. 93, 105536 (2021)

  22. [22]

    Santos et al., Supersolic flow past an obstacle in quasi-two–dimensional Lee-Huang-Yang fluid, Phys.Rev

    G.H. Santos et al., Supersolic flow past an obstacle in quasi-two–dimensional Lee-Huang-Yang fluid, Phys.Rev. A 112, 033318 (2025)

  23. [23]

    B. Liu, H. F. Zhang, R.X. Zhong, X.L. Zhang, X.Z. Qin, C. Huang, Y.Y. Li, and B. A. Malomed, Symmetry breaking of quantum droplets in a dual-core trap, Phys. Rev. A 99, 053602 ( 2019)

  24. [24]

    Z. Chen, Y. Li, B. A. Malomed, and L. Salasnich, Spon- taneous symmetry breaking of fundamental states, vor- tices, and dipoles in two- and one-dimensional linearly coupled traps with cubic self-attraction, Phys. Rev. A 96, 033621, (2017)

  25. [25]

    T. G. Skov, M. G. Skou, N. B. Jørgensen, and J. J. Arlt, Observation of a Lee-Huang-Yang Fluid, Phys. Rev. Lett. 126, 230404 (2021)

  26. [26]

    S. H. Strogatz, Nonlinear Dynamics and Chaos: With Applications to Physics, Biology, Chemistry and Engi- neering, CRC Press, Boca Raton, FL, (2018)

  27. [27]

    Albuch and B

    L. Albuch and B. A. Malomed, Transitions between sym- metric and asymmetric solitons in dual-core systems with cubic-quintic nonlinearity, Math. Comput. Simul. 74 (4- 5), 312-322 (2007)

  28. [28]

    Par´ e and M

    C. Par´ e and M. Florjanczyk,Approximate model of soli- ton dynamics in all-optical couplers, Phys. Rev. A 41 6287 (1990)

  29. [29]

    Sh. R. Otajonov, E. N. Tsoy, and F. Kh. Abdullaev, Stationary and dynamical properties of one-dimensional quantum droplets, Phys. Lett. A 383, 125980 (2019); L. Lavoine and T. Bourdel, Beyond-mean-field crossover from one dimension to three dimensions in quantum droplets of binary mixtures, Phys. Rev. A 103, 033312 (2021). 18

  30. [30]

    B. B. Baizakov, A. Bouketir, A. Messikh, A. Benseghir, and B. A. Pumarov, Variational analysis of flat-top soli- tons in Bose-Einstein condensates, International Journal of Modern Physics B 25 18, 2427-2440 (2011); Sh. R. Otajonov, E. N. Tsoy, and F. Kh. Abdullaev, Variational approximation for two-dimensional quantum droplets, Phys. Rev. E 102, 062217 (20...

  31. [31]

    Vakhitov, A.A

    N.G. Vakhitov, A.A. Kolokolov, Stationary solutions of the wave equation in a medium with nonlinearity satura- tion, Radiophys Quantum Electron. 16, 783–789 (1973)

  32. [32]

    Andreev and E

    A.F. Andreev and E. P. Bashkin, Three-velocity hydro- dynamics of superfluid solutions, Sov. Phys.-JETP 42 164-7, (1976)

  33. [33]

    Nespolo, G

    J. Nespolo, G. E. Astrakharchik, and A. Recati, Andreev- Bashkin effect in superfluid cold gases mixtures, New J. Phys. 19, 125005 (2017)

  34. [34]

    R. M. Caplan, Q. Hoq, R. Carretero-Gonz´ alez, and P. G. Kevrekidis, Azimuthal modulational instability of vor- tices in the nonlinear Schr¨ odinger equation, Optics Com- munications 282, 1399 (2009)

  35. [35]

    Y. Li, Z. Chen, Z. Luo, C. Huang, H. Tan, W. Pang, and B. A. Malomed, Two-dimensional vortex quantum droplets, Phys. Rev. A 98, 063602 (2018)

  36. [36]

    C. R. Cabrera, L. Tanzi, J. Sanz, B. Naylor, P. Thomas, P. Cheiney, L. Tarruell, Quantum liquid droplets in a mixture of Bose-Einstein condensates, Science 359, 301 (2018)

  37. [37]

    Cheiney, C

    P. Cheiney, C. R. Cabrera, J. Sanz, B. Naylor, L. Tanzi, and L. Tarruell, Bright soliton to quantum droplet tran- sition in a mixture of Bose-Einstein condensates, Phys. Rev. Lett. 120, 135301 (2018)

  38. [38]

    Masalaeva, W

    N. Masalaeva, W. Kirkby, F. Ferlaino, and R. N. Bis- set, Quantum vortex channels as Josephson junctions, preprint: https://arxiv.org/pdf/2602.01889 (2026)

  39. [39]

    V. S. Shchesnovich, B. A. Malomed, and R. A. Kraenkel, Solitons in Bose-Einstein condensates trapped in a double-well potential, Physica D 188, 213 (2004). Appendix A: Derivation of the Model Equation Let us consider a three-dimensional two-component Bose-Einstein condensate confined in a double-pancake trap and including the beyond-mean-field Lee-Huang- Ya...