UBC Theses and Dissertations
Vortex structures in neutron stars : or how I learned to stop worrying and just write it already Charbonneau, James
We suggest a mechanism that may resolve a conflict between the precession of a neutron star and the widely accepted idea that protons in the bulk of the neutron star form a type-II superconductor. We will show that if there is a persistent, non-dissipating current running along the magnetic flux tubes the force between magnetic flux tubes may be attractive, resulting in a type-I, rather than a type-II, superconductor. If this is the case, the conflict between the observed precession and the canonical estimation of the Landau-Ginzburg parameter κ > 1 /[square root of 2] (which suggests type-II behaviour) will automatically be resolved. We calculate the interaction between two vortices, each carrying a current j , and demonstrate that when j > [formula omitted], where q is the charge of the Cooper pair and λ is the Meissner penetration depth, a superconductor is always type-I, even when the cannonical [sic] Landau- Ginzburg parameter κ indicates type-II behaviour. If this condition is met, the magnetic field is completely expelled from the superconducting regions of the neutron star. This leads to the formation of the an intermediate state, where alternating domains of superconducting matter and normal matter coexist. We also discuss how these currents might lead to more exotic vortex structures in neutron stars.
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