Can there be a quark matter core in a magnetar? art. no. 043006

The effects of a strong quantizing magnetic field on the nucleation of quar k 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 p hase diverges logarithmically. As a consequence there cannot be a first ord er transition to the quark phase. However, a metal-insulator type of second order transition is possible unless the field strength exceeds 10(20) G. T he study of the chemical evolution of a newborn quark phase shows that in b eta equilibrium the system becomes energetically unstable.