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Description
Pulsar glitches are sudden quasi-periodic increases in the rotation frequency of neutron stars, and are believed to originate from the dynamics of quantized vortices in the neutron superfluid interior. Recently, the vortex network model proposed by Marmorini et al.(2024) suggested that the coupling between $^3P_2$ half-quantized vortices (HQVs) in the outer core and $^1S_0$ singly-quantized vortices (SQVs) in the inner crust gives rise to a large-scale vortex network, providing a candidate mechanism for the diversity of observed glitch phenomena. However, the microscopic nature of this HQV-SQV interaction has not been investigated.
Using the Gross-Pitaevskii framework for the two-component $^1S_0$-$^3P_2$ coexistence phase, we perform two-dimensional simulations varying the density-density and Josephson coupling constants. We find that the Josephson term, arising from the relative phase between the two condensates, dominates over the density-density coupling and induces a strong HQV-SQV attraction. The resulting HQV-SQV-HQV bound state provides microscopic support for the boojum structure at the crust-core boundary envisioned in the vortex network model, and opens a new avenue for understanding the microscopic origin of vortex coupling relevant to pulsar glitch phenomena.
| Category | Theory |
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