Bistability and Competition of Spatiotemporal Chaotic and Fixed Point Attractors in Rayleigh-Bénard Convection

For Rayleigh-Bénard convection in a square cell with a fluid of Prandtl number σ≈1, we report experimental results on the bistability of the spatiotemporal chaotic state of spiral defect chaos (SDC) and a stationary state of ideal straight rolls (ISR). We present the first large aspect ratio experimental confirmation of the theoretical prediction of stable ISR in the parameter regime where typical initial conditions lead to SDC. As a function of the control parameter and for typical experimental initial conditions, we also find a transition in the selection between SDC and ISR which is mediated by front propagation. We characterize the transition with two measures, the spatial correlation length and the spectral pattern entropy, and find that the transition shows similarities to equilibrium phase transitions.