Can there be a quark matter core in a magnetar?

Abstract

The effects of a strong quantizing magnetic field on the nucleation of quark matter droplets and on the chemical evolution of a nascent quark phase at the core of a magnetar are investigated. The surface energy of the quark phase diverges logarithmically. As a consequence there cannot be a first order transition to the quark phase. However, a metal-insulator type of second order transition is possible unless the field strength exceeds ${10}^{20}$ G. The study of the chemical evolution of a newborn quark phase shows that in $\ensuremath{\beta}$ equilibrium the system becomes energetically unstable.