1307.5566 (Joseph Maciejko et al.)

Topological order in a correlated three-dimensional topological
insulator    [PDF]

Joseph Maciejko, Victor Chua, Gregory A. Fiete

Motivated by experimental progress in the growth of heavy transition metal oxides, we theoretically study a microscopic model of interacting fermions on the pyrochlore lattice in the presence of strong spin-orbit coupling. Focusing on intermediate strength interactions, we derive an effective low-energy theory for a fully gapped, topologically ordered, fractionalized state with an eight-fold ground state degeneracy. The topological terms in this theory describe a quantized magnetoelectric response and nontrivial mutual braiding statistics of dynamical extended vortex loops with emergent fermions in the bulk. Starting from our microscopic model, we explicitly compute the expected mutual statistics within a slave-particle mean-field theory. We argue that our model also provides a possible materials platform for oblique confinement.

View original: http://arxiv.org/abs/1307.5566