Novel mechanism for type I superconductivity in neutron stars

Abstract

We suggest a mechanism that may resolve a conflict between the precession of a neutron star and the widely accepted idea that protons in the bulk of the neutron star form a type II superconductor. We will show that if there is a persistent, nondissipating current running along the magnetic flux tubes the force between magnetic flux tubes may be attractive, resulting in a type I, rather than a type II, superconductor. If this is the case, the conflict between the observed precession and the canonical estimation of the Landau-Ginzburg parameter κ > 1/ √ 2 (which suggests type-II behavior) will automatically be resolved. We calculate the interaction between two vortices, each carrying a current j , and demonstrate that when j >¯h c 2qλ , where q is the charge of the Cooper pair and λ is the Meissner penetration depth, a superconductor is always type-I, even when the cannonical Landau-Ginzburg parameter κ indicates type II behavior. If this condition is met, the magnetic field is completely expelled from the superconducting regions of the neutron star. This leads to the formation of the intermediate state, where alternating domains of superconducting matter and normal matter coexist. We further argue that even when the induced current is small j <¯h c 2qλ the vortex Abrikosov lattice will nevertheless be destroyed due to the helical instability studied previously in many condensed matter systems. This would also resolve the apparent contradiction with the precession of the neutron stars. We also discuss some instances where anomalous induced currents may play a crucial role, such as in neutron star kicks, pulsar glitches, the toroidal magnetic field and the magnetic helicity.

Chiral asymmetry of the Fermi surface in dense relativistic matter in a magnetic field

“…As we show, an external magnetic field induces two qualitatively different contributions to the net axial current in the normal phase of dense relativistic matter. The first one is a topological contribution due to the lowest Landau level (LLL) that was previously discussed in the literature [6,7,8,9]. It exists even in free theories.…”

Chiral magnetic conductivity

“…Implications of the Chiral Magnetic Effect on astrophysical phenomena have recently been discussed in Ref. [27]; another astrophysical implication can be found in [28].…”

“…(25) and the properties of the chirality projection operators the integrand of Eq. (27) can now be written as…”

Local violation effects and thermalization in QCD: Views from quantum field theory and holography

“…Closely related phenomena have been previously discussed in the physics of neutrinos [19] and quantum wires [20]. In QCD context formula (1) has been used in applications to neutron star physics where magnetic field is known to be large, and the corresponding (µ L − µ R ) = 0 can be generated in neutron star environment as a result of continuos P violating processes happening in nuclear matter [21,22]. It has been also applied to heavy ion collisions where an effective (µ L − µ R ) = 0 is locally induced.…”