Chaos in a Complex Plasma

Chaotic dynamics is found experimentally in a complex (dusty) plasma disk of three particles. A sinusoidal modulation of the plasma density excites both the center-of-mass and breathing modes. Low-dimensional chaos is seen for a 1:2 resonance between these modes. The dimension of the attractor is found to be 2.48 $\pm$ 0.05, while the largest positive Lyapunov exponent is 0.17 $\pm$ 0.04 bits/sample.