Raman scattering in a superlattice under an electric field

An electric field is applied to a superlattice in the growth direction. While the phonon parity selection rules break down, the selection rules for scattering mechanisms in various polarization configurations are still in effect for zero field. Numerical estimates show that Raman scattering due to normally parity-forbidden phonon modes can dominate that due to allowed modes in large but realizable electric fields.