  We present a theory of three dimensional fractionalized topological
insulators in the form of U(1) spin liquids with gapped fermionic spinons in
the bulk and topologically protected gapless spinon surface states. Starting
from a 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 representation
of the spins, can naturally give rise to an emergent spin-orbit coupling for
the spinons. This stabilizes a fractionalized topological insulators which also
have bulk bond spin-nematic order. Finally, we describe the low energy
properties of these states.

Strongly Correlated Electrons