Interference between four-wave and six-wave mixing in resonant coherent scattering from biexcitons in CuCl

We present the first evidence of interference between four- and six-wave mixing in multiple coherent scattering near the two-photon resonance of biexcitons in CuCl. The experimental data are quantitatively explained by taking proper account of propagation effects and by a model for ${\chi }^{\mathrm{}\left(5\right)\mathrm{}}$ involving no adjustable parameters.