  We investigate the possible types of coupling between ferroelectricity and
magnetism for the zig-zag spin chain multiferroic LiCu2O2 compound. We
construct a multi-order parameter phenomenological model for the material based
on a group theoretical analysis. From our calculation we conclude that a
coupling involving the inter-chain magnetic structure and ferroelectricity is
necessary to understand the experimental results of Park et.al. Our proposed
model is able to account for the electric polarization flop in the presence of
an externally applied magnetic field. Furthermore, based on our theoretical
model we can make specific selection rule predictions about electromagnon
excitations present in the LiCu2O2 system. We also predict that the
electromagnon peaks measured in an ac-conductivity measurement are field
dependent.
