Magnetar Formation, Helicity, and the Chiral Magnetic Effect

Magnetars have the strongest magnetic fields known, and the large-scale dipoles we infer from their spin-down are what define them. Yet newborn neutron stars are expected to emerge from turbulent dynamos with mostly small-scale, tangled fields, and simulations show that birth conditions alone cannot produce such strong dipoles. Something must move magnetic energy from small to large scales during the star’s life. My work explores how this happens. Magnetic helicity, the twist and linkage of field lines, naturally pushes energy towards larger scales. A quantum effect of the dense electron plasma, the chiral magnetic effect, goes further: it can reorganise tangled fields into magnetar-strength dipoles within decades, offering a physical explanation for how magnetars are born.