Existence, stability, and dynamics of monopole and Alice ring solutions in antiferromagnetic spinor condensates
Existence, stability, and dynamics of monopole and Alice ring solutions in antiferromagnetic spinor condensates
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DOI：
10.1103/physreva.105.053303
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发表时间：
2022-05-11
影响因子：
2.9
通讯作者：
Kevrekidis, P. G.
中科院分区：
文献类型：
--
作者：
Mithun, Thudiyangal;Carretero-Gonzalez, R.;Kevrekidis, P. G.
在这篇论文中。我们研究了F=1(23)Na旋量凝聚的反铁磁极性相中选择的拓扑点和线缺陷的存在性、稳定性和动力学。具体地说，我们利用三维空间中的固定点和数值延拓技术来识别单极子和Alice环的解族，因为化学势(原子数)和捕获强度在可实现的实验参数的间隔内是不同的。我们能够沿着单极从小原子数的线性极限一直到大原子数的托马斯-费米体系。此外，重要的是，我们的研究揭示了存在两个Alice环溶液分支，对应于相对较小和较大的环半径，随着化学势的变化，这两个分支在鞍心分支中彼此分叉。我们发现，在所考虑的区域内，单极子解总是动态不稳定的。相反，我们发现较大的Alice环在分叉点附近确实是稳定的，直到它从一个振荡的不稳定气泡失稳到较大的化学势。我们还报道了通过改变俘获强度来显著降低但不是完全消除较小Alice环的不稳定性的可能性。通过直接数值模拟，探讨了不同失稳波形的动态演化规律。
In this paper. we study the existence, stability, and dynamics of select topological points and line defects in antiferromagnetic, polar phase, F = 1( 23)Na spinor condensates. Specifically, we leverage fixed-point and numerical continuation techniques in three spatial dimensions to identify solution families of monopole and Alice rings as the chemical potential (number of atoms) and trapping strengths are varied within intervals of realizable experimental parameters. We are able to follow the monopole from the linear limit of small atom number all the way to the Thomas-Fermi regime of large atom number. Additionally, and importantly, our studies reveal the existence of two Alice ring solution branches, corresponding to, relatively, smaller and larger ring radii, that bifurcate from each other in a saddle-center bifurcation as the chemical potential is varied. We find that the monopole solution is always dynamically unstable in the regimes considered. In contrast, we find that the larger Alice ring is indeed stable close to the bifurcation point until it destabilizes from an oscillatory instability bubble for a larger value of the chemical potential. We also report on the possibility of dramatically reducing, yet not completely eliminating, the instability rates for the smaller Alice ring by varying the trapping strengths. The dynamical evolution of the different unstable waveforms is also probed via direct numerical simulations.