Composite cores of monopoles and Alice rings in spin-2 Bose-Einstein condensates

Research output: Working paperPreprint

Abstract

We show that energy relaxation causes a point defect in the uniaxial-nematic phase of a spin-2 Bose-Einstein condensate to deform into a spin-Alice ring that exhibits a composite core structure with distinct topology at short and long distances from the singular line. An outer biaxial-nematic core exhibits a spin half-quantum vortex structure with a uniaxial-nematic inner core. By numerical simulation we demonstrate a dynamical oscillation between the spin-Alice ring and a split-core hedgehog configuration via the appearance of ferromagnetic rings with associated vorticity inside an extended core region. We further show that a similar dynamics is exhibited by a spin-Alice ring surrounding a spin-vortex line resulting from the relaxation of a monopole situated on a spin-vortex line in the biaxial-nematic phase. In the cyclic phase similar states are shown instead to form extended phase-mixing cores containing rings with fractional mass circulation or cores whose spatial shape reflect the order-parameter symmetry of cyclic inner core, depending on the initial configuration
Original languageEnglish
DOIs
Publication statusPublished - 8 Jan 2024

Publication series

NamePhysical Review Research
PublisherAmerican Physical Society

Keywords

  • cond-mat.soft
  • hep-th
  • quant-ph

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