Cai, RG (reprint author), Chinese Acad Sci, Inst Theoret Phys, State Key Lab Theoret Phys, Beijing 100190, Peoples R China.
In this paper we build a holographic model of paramagnetism/antiferromagnetism phase transition, which is realized by introducing two real antisymmetric tensor fields coupling to the background gauge field strength and interacting with each other in a dyonic black brane background. In the case without an external magnetic field and in low temperatures, the magnetic moments condense spontaneously in an antiparallel manner with the same magnitude and the time reversal symmetry is also broken spontaneously (if the boundary spatial dimension is more than 2, spatial rotational symmetry is broken spontaneously as well), which leads to an antiferromagnetic phase. In the case with the weak external magnetic field, the magnetic susceptibility density has a peak at the critical temperature and satisfies the Curie-Weiss law in the paramagnetic phase of antiferromagnetism. In the strong external magnetic field case, there is a critical magnetic field B-c in the antiferromagnetic phase: when the magnetic field reaches Bc, the system will return into the paramagnetic phase by a second order phase transition.