Finite temperature effects on anisotropic pressure and equation of state of dense neutron matter in an ultrastrong magnetic field

Abstract

Spin polarized states in dense neutron matter with recently developed Skyrme effective interaction (BSk20 parametrization) are considered in the magnetic fields $H$ up to $10^{20}$ G at finite temperature. In a strong magnetic field, the total pressure in neutron matter is anisotropic, and the difference between the pressures parallel and perpendicular to the field direction becomes significant at $H>H_{th}\sim 10^{18}$ G. The longitudinal pressure decreases with the magnetic field and vanishes in the critical field $10^{18}<H_c\lesssim 10^{19}$ G, resulting in the longitudinal instability of neutron matter. With increasing the temperature, the threshold $H_{th}$ and critical $H_c$ magnetic fields also increase. The appearance of the longitudinal instability prevents the formation of a fully spin polarized state in neutron matter and only the states with moderate spin polarization are accessible. The anisotropic equation of state is determined at densities and temperatures relevant for the interiors of magnetars. The entropy of strongly magnetized neutron matter turns out to be larger than the entropy of the nonpolarized matter. This is caused by some specific details in the dependence of the entropy on the effective masses of neutrons with spin up and spin down in a polarized state.

13 pages, 13 figures; an extension of arXiv:1112.5420 to finite temperatures. V2: added acknowledgement

References in corpus (11)

• Further explorations of Skyrme-Hartree-Fock-Bogoliubov mass formulas. XII: Stiffness and stability of neutron-star matter
• Equation of State of a Dense and Magnetized Fermion System
• Spin and spin-isospin instabilities in asymmetric nuclear matter at zero and finite temperatures using Skyrme functionals
• Spin polarized neutron matter within the Dirac-Brueckner-Hartree-Fock approach
• Magnetization of a neutron plasma with Skyrme and Gogny forces in the presence of a strong magnetic field
• Spin ordered phase transitions in isospin asymmetric nuclear matter
• Lowest order constrained variational calculation of polarized neutron matter at finite temperature
• Unusual temperature behavior of entropy of antiferromagnetic spin state in nuclear matter with effective finite range interaction
• Finite temperature effects on spin polarization of neutron matter in a strong magnetic field
• Spin- and isospin-polarized states of nuclear matter in the Dirac-Brueckner-Hartree-Fock model
• Phase transition to the state with nonzero average helicity in dense neutron matter

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