Axionic Antiferromagnetic Insulator Phase in a Correlated and Spin-Orbit   Coupled System
  We study theoretically a three-dimensional correlated and spin-orbit coupled system, the half-filled extended Fu-Kane-Mele-Hubbard model on a diamond lattice, focusing on the topological magnetoelectric response of the antiferromagnetic insulator phase. In the antiferromagnetic insulator phase, the Dirac-like low-energy effective Hamiltonian is obtained. Then the theta term, which results in the magnetoelectric response, is derived as a consequence of the chiral anomaly. The realization of the dynamical axion field in our model is discussed. The relation with a symmetry broken phase induced by interactions in lattice quantum chromodynamics is also discussed. 
Akihiko Sekine and Kentaro Nomura
cond-mat.str-el cond-mat.mes-hall cond-mat.mtrl-sci hep-ph