Stable higher-order vortex quantum droplets in an annular potential

• DOI: 10.1016/j.chaos.2024.114472
• Publication Date: 2024-01-18T00:05:16Z
• Authors: Liangwei Dong; Mingjing Fan; Boris A. Malomed
• Keywords: Condensed Matter - Quantum Gases; Nonlinear Sciences - Pattern Formation and Solitons

We address the existence, stability, and evolution of two-dimensional vortex quantum droplets (VQDs) in binary Bose-Einstein condensates trapped in a ring-shaped potential. The interplay of the Lee-Huang-Yang-amended nonlinearity and trapping potential supports two VQD branches, controlled by the radius, width and depth of the potential profile. While the lower-branch VQDs, bifurcating from the system's linear modes, are completely unstable, the upper branch is fully stable for all values of the topological charge $m$ and potential's parameters. Up to $m=12$ (at least), stable VQDs obey the {\it anti-Vakhitov-Kolokolov} criterion. In the limit of an extremely tight radial trap, the modulational instability of the quasi-1D azimuthal VQDs is studied analytically. We thus put forward an effective way to produce stable VQDs with higher vorticity but a relatively small number of atoms, which is favorable for experimental realization.<br/>Comment: 8 pages, 5 figures, to be published in Chaos, Solitons and Fractals<br/>