2011/12/12 by A. A. Isayev, J. Yang
Earth and Planetary Sciences · Physics and Astronomy · #Anisotropy #Atomic and Subatomic Physics Research #Condensed matter physics #Electron #Equation of state #High-pressure geophysics and materials #Magnetar #Magnetic field #Neutron #Neutron star #Nuclear physics #Physics #Pulsars and Gravitational Waves Research #Quantum mechanics #Spin polarization #astro-ph.HE #nucl-th
paper · pdf · doi:10.1103/physrevc.84.065802
published as Phys.Rev. C84:065802,2011 · 13 pages, 13 figures; an extension of arXiv:1112.5420 to finite temperatures. V2: added acknowledgement
openalex publication_date 2011/12/12 · arxiv created 2013/01/04 · arxiv updated 2015/02/02 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Spin-polarized states in dense neutron matter with the recently developed Skyrme effective interaction (BSk20 parametrization) are considered in the magnetic fields H up to 1020 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>Hth\ensuremath∼1018 G. The longitudinal pressure decreases with the magnetic field and vanishes in the critical field 1018<Hc\ensuremath\lesssim1019 G, resulting in the longitudinal instability of neutron matter. With increasing temperature, the threshold Hth and critical Hc 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 to the interiors of magnetars. The entropy of strongly magnetized neutron matter turns out to be larger than the entropy of 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.