On the theory of superfluidity of dense neutron matter with anisotropic spin-triplet p-wave pairing in strong magnetic fields
National Science Center “Kharkov Institute of Physics and Technology” 1 Akademicheskaya Str., Kharkov 61108, Ukrain
Received June 5, 2017
The previously derived nonlinear integral equations for the components of the order parameter (OP) of dense superfluid neutron matter (SNM) with anisotropic spin-triplet p-wave pairing (similar to 3He-A) and with taking into account the effects of magnetic field and finite temperatures are reduced here to the equations for the two components of OP in the limit of zero temperature. These equations (which are valid for arbitrary parametrization of the effective Skyrme interaction in neutron matter) are specified and solved numerically for the generalized BSk21 parametrization of the effective Skyrme forces (with additional terms dependent on density n) in neutron matter. As the main result the splitting (nonlinearly growing due to the effect of moderately strong magnetic field H) of the energy gap (in the energy spectrum of neutrons in SNM) is calculated as nonlinear function of density n in the limiting case of zero temperature. A small asymmetry (nonlinearly growing with magnetic field) of the energy gap splitting is also obtained in the range of moderately strong magnetic fields 1016 G ≤ H ≤ 1017 G. Phase transitions in neutron matter to superfluid states of such type and so strong magnetic fields might occur (and exist) at subnuclear and supranuclear densities as in liquid outer core of magnetars (strongly magnetized neutron stars).
PACS: 21.65.Cd Asymmetric matter, neutron matter;
Key words: superfluid Fermi liquid, spin-triplet pairing, dense neutron matter, generalized Skyrme forces, strong magnetic fields.
Published online: February 26, 2018