Magnetic Properties of Quantized Vortices in Neutron $^3P_2$ Superfluids in Neutron Stars

TL;DR

This paper investigates the magnetic properties of quantized vortices in neutron $^3P_2$ superfluids within neutron stars, revealing spontaneous core magnetization but negligible overall magnetic field effects.

Contribution

It introduces a Ginzburg-Landau model for $^3P_2$ superfluids and numerically constructs vortex solutions under magnetic fields, highlighting spontaneous magnetization phenomena.

Findings

Vortex cores can spontaneously magnetize with fields around 10^7-8 Gauss.

Net magnetic field in neutron stars remains negligible due to vortex lattice scale.

Vortex structures depend on external magnetic field orientation and strength.

Abstract

We discuss quantized vortices in neutron $^3P_2$ superfluids, which are believed to realize in high density neutron matter such as neutron stars. By using the Ginzburg-Landau free energy for $^3P_2$ superfluids, we determine the ground state in the absence and presence of the external magnetic field, and numerically construct $^3P_2$ quantized vortices in the absence and presence of the external magnetic field along the vortex axis (poloidal) or angular direction (toroidal). We find in certain situations the spontaneous magnetization of the vortex core, whose typical magnitude is about $10^{7-8}$ Gauss, but the net magnetic field in a neutron star is negligible because of the ratio of the vortex core size $\sim 10$fm and the intervortex distance $\sim 10^{-6}$m in a vortex lattice.