  We discuss the problem of characterizing "quantum disordered" ground states,
obtained upon loss of antiferromagnetic order on general lattices in two
spatial dimensions, with arbitrary electronic band structure. A key result is
the response in electron bilinears to the skyrmion density in the local
antiferromagnetic order, induced by geometric phases. We also discuss the
connection to topological terms obtained under situations where the electronic
spectrum has a Dirac form.
