Vector-boson condensates, spin-triplet superfluidity of paired neutral and charged fermions, and 3P2 pairing of nucleons

Abstract

After reminding of properties of the condensate of the complex scalar field in the external uniform magnetic field H focus is made on the study of phases of the complex neutral vector boson fields coupled with magnetic field by the Zeeman coupling and phases of the charged vector boson fields. These systems may behave as nonmagnetic and ferromagnetic superfluids and ordinary and ferromagnetic superconductors. Response of the ferromagnetic superfluid and superconducting systems occupying half of space on the external uniform static magnetic field H is thoroughly studied. Then the spin-triplet pairing of neutral fermions at conserved spin is considered. Novel phases are found. In external magnetic field the phase with zero mean spin proves to be unstable to the formation of a phase with a non-zero spin. For H > Hcr2 the spin-triplet pairing and ferromagnetic superfluidity continue to exist above the "old" phase transition critical temperature Tcr. For a certain parameter choice ferromagnetic superfluid phases are formed already for H = 0, characterized by an own magnetic field h. Formation of domains is discussed. Next, spin-triplet pairing of charged fermions is studied. Novel phases are found with a ferromagnetic superconductivity. Then, the 3P2 nn pairing in neutron star matter is studied. Also a 3P2 pp pairing is considered. Numerical estimates are performed in the BCS weak coupling limit and beyond it for the 3P2 nn and pp pairings, as well as for the 3S1 np pairing.

Oscillating Magnetized Color Superconducting Quark Stars

“…In NSs, superconductivity may be accompanied by the baryon superfluidity and/or the electromagnetic Meissner effect Shovkovy (2005), and the MF can be expelled during a long time period Baym et al (1969) or may exist in vortices Haskell and Sedrakian (2018). In the case of pairing in P-wave states, the superfluidity/superconductivity may remain for B > B c2 , as in ferromagnetic superconductors and in some color superconducting phases Voskresensky (2020).…”

Oscillating Magnetized Color Superconducting Quark Stars

“…In NSs, superconductivity may be accompanied by the baryon superfluidity and/or the electromagnetic Meissner effect [70], and the MF can be expelled during a long time period [71] or may exist in vortices [72]. In the case of pairing in P-wave states, the superfluidity/superconductivity may remain for B > B c2 , as in ferromagnetic superconductors and in some color superconducting phases [73].…”

Evolution of Quasiperiodic Structures in a Non-Ideal Hydrodynamic Description of Phase Transitions

“…Formation of the pasta non-uniform phases is one of the possibilities [31,35,36]. Add here possibilities of the phase transitions between various superfluid [37,38] and ferromagnetic-superfluid [39] phases in the cold neutron stars and in the color-superconducting hybrid compact stars [40], as well as numerous possibilities of the phase transitions in the condensed matter physics at terrestrial conditions, like liquid-gas, liquid-glass, glass-metal transitions, etc.…”