Fractionalized topological insulators from frustrated spin models in three dimensions

We present the theory of a three-dimensional fractionalized topological insulator in the form of a U(1) spin liquid with gapped fermionic spinons in the bulk and topologically protected gapless spinon surface states. Starting from a spin-rotation-invariant spin-1/2 model on a pyrochlore lattice with frustrated antiferromagnetic and ferromagnetic exchange interactions, we show that decomposition of the latter interactions, within slave-fermion …