Conduction delays in switchingNbSe3: Sensitive dependence on the initial configuration

In switching charge-density-wave (CDW) conductors, a voltage pulse greater than threshold causes the CDW to slide only after a delay τ. For identical experimental conditions, we have found a class of delays as long as 5 s with fluctuations as large as 5 orders of magnitude. For large τ, the distribution of delays N(τ)∝${\mathrm{\tau }}^{\mathrm{-}\gamma }$, with 0.8<γ<1.3. We argue that τ measures the time at which the internal strain somewhere in the CDW exceeds the threshold for phase slippage. The electronic history of the sample, and hence the distribution of initial configurations of the CDW, determines N(τ).