TY - JOUR
T1 - Spin-polarized phases of superfluids in neutron stars
AU - Mizushima, Takeshi
AU - Yasui, Shigehiro
AU - Inotani, Daisuke
AU - Nitta, Muneto
N1 - Funding Information:
Japan Society for the Promotion of Science Ministry of Education, Culture, Sports, Science and Technology RIKEN Fujukai Foundndation
Funding Information:
We thank Michikazu Kobayashi for useful discussion. T.M. is supported by a Grant-in-Aid for Scientific Research on Innovative Areas “Quantum Liquid Crystals” (Grant No. JP20H05163) from the Japan Society for the Promotion of Science (JSPS), and JSPS KAKENHI (Grants No. JP20K03860, No. JP20H01857, and No. JP21H01039). The work of S.Y., D.I., and M.N. was supported by the Ministry of Education, Culture, Sports, Science and Technology supported Program for the Strategic Research Foundation at Private Universities Topological Science (Grant No. S1511006). S.Y. is supported by JSPS KAKENHI (Grant No. JP17K05435) and the Interdisciplinary Theoretical and Mathematical Sciences Program at RIKEN. D.I. is supported by the Financial Support of Fujukai Foundndation, and M.N. is supported in part by JSPS KAKENHI (Grant No. JP18H01217).
Publisher Copyright:
©2021 American Physical Society
PY - 2021/10
Y1 - 2021/10
N2 - The interior of a neutron star is expected to be occupied by a neutron superfluid, which is the condensate of spin-triplet -wave Cooper pairs of neutrons with total angular momentum . Here we investigate the thermodynamic stability of superfluids in a neutron-star interior under a strong magnetic field. Using the theory incorporating the finite-size correction of the neutron Fermi surface, we show that the spin-polarized phases of superfluids, the magnetized biaxial nematic phase, and the ferromagnetic phase appear in high temperatures and high magnetic fields. These phases were missed in the previous studies using the quasiclassical approximation in which dispersions of neutrons are linearized around the Fermi surface. In particular, the ferromagnetic phase, which is the condensation of Cooper-paired neutrons with fully polarized spins, appears between the normal phase and the biaxial nematic phase and enlarges the thermodynamic stability of superfluids under strong magnetic fields. Furthermore, we present the augmented Ginzburg-Landau theory that incorporates the thermodynamic stability of spin-polarized superfluid phases.
AB - The interior of a neutron star is expected to be occupied by a neutron superfluid, which is the condensate of spin-triplet -wave Cooper pairs of neutrons with total angular momentum . Here we investigate the thermodynamic stability of superfluids in a neutron-star interior under a strong magnetic field. Using the theory incorporating the finite-size correction of the neutron Fermi surface, we show that the spin-polarized phases of superfluids, the magnetized biaxial nematic phase, and the ferromagnetic phase appear in high temperatures and high magnetic fields. These phases were missed in the previous studies using the quasiclassical approximation in which dispersions of neutrons are linearized around the Fermi surface. In particular, the ferromagnetic phase, which is the condensation of Cooper-paired neutrons with fully polarized spins, appears between the normal phase and the biaxial nematic phase and enlarges the thermodynamic stability of superfluids under strong magnetic fields. Furthermore, we present the augmented Ginzburg-Landau theory that incorporates the thermodynamic stability of spin-polarized superfluid phases.
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U2 - 10.1103/PhysRevC.104.045803
DO - 10.1103/PhysRevC.104.045803
M3 - Article
AN - SCOPUS:85117408412
SN - 2469-9985
VL - 104
JO - Physical Review C
JF - Physical Review C
IS - 4
M1 - 045803
ER -