1/f noise and avalanche scaling in plastic deformation

We study the intermittency and noise of dislocation systems undergoing shear deformation. Simulations of a simple two-dimensional discrete dislocation dynamics model indicate that the deformation rate exhibits a power spectrum scaling of the type 1/f(alpha). The noise exponent is far away from a Lorentzian, with alpha approximate to 1.5. This result is directly related to the way the durations of avalanches of plastic deformation activity scale with their size.