Ferromagnetism of quark liquid

Usually it is believed that the Hartree–Fock state of quark matter is a Fermi gas state with no polarization of spins. We examine the possibility of the polarized quark liquid interacting with the one-gluon-exchange interaction. It is suggested that the Hartree–Fock state shows a spontaneous magnetic instability at low densities through the same mechanism as in electron gas. Metastability of the polarized quark liquid is also discussed.