Observation of antibound biexciton states in a single ZnSe quantum well

We show evidence for the experimental observation of antibound excitonic molecular states. The samples were grown as a ZnSe-ZnSSe-ZnMgSSe separate confinement heterostructure, including the single 75-A-thick QW. Transmission measurements at T=10 K showed a QW exciton with peak value of the absorption coefficient, and a linewidth of 0.5 meV. Spectrally resolved, time-integrated four wave mixing (FWM) experiments were performed in a degenerate two-beam geometry.