Abstract
We study the electromagnetic response of a chiral dxy+idx2- y2 density wave state. Due to parity (
) and time reversal (
) violation, Chern-Simons terms emerge in the effective action of the U(1) gauge field. As a consequence, electric and magnetic fields are coupled providing the possibility of observing the Spontaneous Quantum Hall Effect, i.e. the generation of Hall voltage via the sole application of an electric field. We demonstrate how the Chern-Simons terms are induced and discuss the topological origin of the quantization of the Hall conductance.