Microscopic calculation of the pinning energy of a vortex in the inner crust of a neutron star

Understand

The structure of a vortex in the inner crust of a pulsar is calculated microscopically in the Wigner-Seitz cell approximation, simulating the conditions of the inner crust of a cold, non-accreting neutron star, in which a lattice of nuclei coexists with a sea of superfluid neutrons.

• The calculation is based on the axially deformed Hartree-Fock-Bogolyubov framework, using effective interactions.
• The present work extends and improves previous studies in four ways: i) it allows for the axial deformation of protons induced by the large deformation of neutrons due to the appearance of vortices; ii) it includes the effect of Coulomb exchange; iii) considers the possible effects of the screening of the pairing interaction; and iv) it improves the numerical treatment.
• We also demonstrate that the binding energy of the nucleus-vortex system can be used as a proxy to the pinning energy of a vortex and discuss in which conditions this applies.