Conduction Noise under Pulsed Electric Field in Nonohmic Regime of NbSe₃

Voltage oscillations under repetitive pulsed fields were measured in the non-ohmic regime of NbSe 3 below 58 K. Crystals used exhibit a narrow-band noise with only one fundamental component under a dc bias. The number of oscillations observed within the pulse width is always integral regardless of the pulse width, and it increases by one whenever the pulse width is increased by a constant value. This phenomenon, which appears to contradict with causality, is considered to be ascribed to some kinds of memory effect in metastable states of charge-density waves.