TAMING SPATIOTEMPORAL CHAOS WITH DISORDER

DISORDER and noise in physical systems usually tend to destroy spatial and temporal regularity, but recent research into nonlinear systems p rovides intriguing counter-examples. In the phenomenon of stochastic r esonance(1), for example, the presence of noise improves the ability o f some nonlinear systems to transfer information reliably. Noise can a lso remove chaos in a model oscillator(2), and facilitate synchronizat ion in an extended array of bistable elements(3). Here we explore the use of disorder as a means to control spatiotemporal chaos(4-8) in cou pled arrays of forced, damped, nonlinear oscillators. Chaotic behaviou r in spatially extended systems, especially in biology and physiology( 9,10), might be amenable to control, as occurs in low-dimensional temp orally chaotic systems(11,12). In our numerical experiments, one- and two-dimensional arrays of identical oscillators behave chaotically, bu t the introduction of slight, uncorrelated differences between the osc illators induces ordered motion characterized by complex but regular s patiotemporal patterns.