Ferromagnetism of electrons in solid quark cluster stars

TL;DR

This paper proposes that electrons in solid quark-cluster stars can spontaneously magnetize, potentially explaining the strong magnetic fields observed in pulsars, though not in magnetars.

Contribution

It introduces a novel ferromagnetic mechanism for electron magnetization in solid quark-cluster stars as a source of pulsar magnetic fields.

Findings

Electrons can spontaneously magnetize under Coulomb repulsion.

Magnetization could produce magnetic fields matching pulsar observations.

The mechanism does not apply to magnetars.

Abstract

In this paper we are trying to solve the problem of the origin of strong magnetic fields in the framework of solid quark-cluster stars. We propose that, under the Coulomb repulsion, the electrons inside the stars could spontaneously magnetized and become ferromagnetic, and hence would contribute non-zero net magnetic momentum to the whole star. The leading order approximation in our simple model shows that the magnetism of solid quark-cluster matter could be possible. For most cases in solid quark-cluster stars, the amount of net magnetic momentum, could be significant, and the net magnetic moments of electron system in solid quark-cluster stars could be large enough to induce the observed magnetic fields for pulsars with $B\sim 10^{11}$ to $\sim 10^{13}$ Gauss. This mechanism of generating magnetic field is not valid for so-called magnetars.