Abstract
The nonlinear interactions of parametrically driven surface waves have been shown to yield a rich family of nonlinear states. When the system is driven by two commensurate frequencies, interesting nonlinear states are generated via a number of different 3-wave resonant interactions. A particularly interesting state bifurcates directly from the featureless state and exhibits highly disordered behavior in both space and time. This state exists within a wide range of phase space and is bordered on either side by superlattice patterns having different temporal parities. We show that: 1. This spatio-temporal chaos is result of competition between degenerate nonlinear states that possess different temporal and spatial symmetries. 2. This state can be stabilized to spatially ordered patterns by the addition of a small amplitude 3rd frequency. The spatial symmetry of the selected pattern is governed by the temporal symmetry of the controlling 3rd frequency used.