Driving Rate Effects on Crackling Noise

Many systems respond to slowly changing external conditions with crackling noise, created by avalanches or pulses with a broad range of sizes. Examples range from Barkhausen noise (BN) in magnets to earthquakes. In this Letter, we discuss the effects of increasing driving rate $\Omega$ on the scaling behavior of the avalanche size and duration distributions as well as qualitative effects of $\Omega$ on the power spectra. We derive an exponent inequality as a criteria for the relevance of $\Omega$. To illustrate these general results, we use recent experiments on BN as a successful example.

Figure 1

Time series of the simulated BN voltage signals for increasing field sweep rates (obtained using the ztneRFIM [13]). At the bottom one can observe separate pulses. As the sweep rate is increased, the pulses merge and become bigger until no separate pulses can be observed.