The problem of a condensate of a relativistic neutral vector boson gas constituted of particles bearing a magnetic moment is discussed. Such a vector boson system is expected to be formed either by parallel spin-pairing of neutrons in a sufficiently strong magnetic field, or by neutral atoms under specific conditions of magnetic field strength and density. A strong self-magnetization arises due to a Bose-Einstein-like condensation. Then the system, which may resemble the superfluid said to exist in the core of neutron stars, becomes more unstable under transverse collapse than the ordinary fermion gas. In the nonrelativistic limit of laboratory conditions, an analogy with the behavior of exploding Bose-Einstein condensates for critical values of magnetic field strength and particle density; reported by several authors, is briefly discussed.
We discuss the bosonization of a relativistic very dense Fermi gas in a magnetic field and the consequent Bose–Einstein condensation of the resulting relativistic vector gas of charged particles. The model may be applied to paired spin-up electrons. We show that such systems may maintain self-consistently magnetic fields of order 10 10 −10 13 G. That pairing could be the origin of large magnetic fields in some white dwarfs and neutron stars. For fields large enough (~10 13 for white dwarfs), the system becomes unstable and collapses.
Abstract We study the thermodynamic properties of a neutral vector boson gas in presence of a constant magnetic field, by means of a semi-classical approach that allows to introduce the spin in the non-relativistic spectrum of the bosons. Bose-Einstein condensation is obtained and it turns out to depend on all the parameters involved in the problem: temperature, particle density and magnetic field. A spontaneous magnetization appears at low temperature as a consequence of the condensed state. The axial symmetry imposed in the system by the magnetic field presence, splits the pressure in two components, one along and another perpendicular to the magnetic axis. Under certain conditions, the perpendicular pressure becomes negative signaling that the system undergoes a transversal magnetic collapse. The spontaneous magnetization might be useful to model magnetic field production inside compact stars, while the negative pressures imposes certain limits to the temperatures and densities needed inside these objects to support a given magnetic field.
The magnetic properties of charged vector boson gas are studied in the very weak, and very strong (near critical value) external magnetic field limits. When the density of the vector boson gas is low, or when the external field is strong, no true Bose–Einstein condensation occurs, though significant amount of bosons will accumulate in the ground state. The gas is ferromagnetic in nature at low temperature. However, Bose–Einstein condensation of vector bosons (scalar bosons as well) is likely to occur in the presence of a uniform weak magnetic field when the gas density is sufficiently high. A transitional density depending on the magnetic field seems to exist below which the vector boson gas changes its property with respect to the Bose–Einstein condensation in a uniform magnetic field.
We discuss the occurrence of Bose-Einstein condensation in systems of noninteracting charged particles in three and one dimensions and in presence of an external magnetic field. In the one dimensional, as well as in the magnetic field cases, although not a critical temperature, a characteristic temperature can be found, corresponding to the case in which the ground state density becomes a macroscopic fraction of the total density. The case of relativistic charged scalar and vector particles is studied. The results give support to the existence of superconductivity in extremely strong magnetic fields, and lead to the prediction of superconductive-ferromagnetic behavior in the vector field case, which might be of interest in condensed matter as well as in cosmology. Some features of the magnetization in the early universe are conjectured.
We discuss the occurrence of Bose-Einstein condensation in systems of noninteracting charged particles in three in one dimensions and in presence of an external magnetic field. In the one dimensional, as well as in the magnetic field cases, although not a critical temperature, a characteristic temperature can be found, corresponding to the case in which the ground state density becomes a macroscopic fraction of the total density. The case of relativistic charged scalar and vector particles is studied. The results obtainedgive support to the existence of superconductivity in extremely strong magnetic fields, and leads to the prediction of superconductive-ferromagnetic behavior in the vector field case, which might be of interest in condensed matter as well as in cosmology. Some features of the magnetization in the early universe are conjectured.
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. The systems may behave as nonmagnetic and ferromagnetic superfluids and ordinary and ferromagnetic superconductors. Response of these 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 nonzero spin. For a certain parameter choice ferromagnetic superfluid phases are formed already for
H=0, characterized by an own magnetic field
h. For
H>Hcr2, the spin-triplet pairing and ferromagnetic superfluidity continue to exist above the ``old'' phase transition critical temperature
Tcr. Formation of domains is discussed. Next, spin-triplet pairing of charged fermions is studied. Novel phases are found. 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.