Metastable States and CDW Conductivity in NbSe3

A study of the response of niobium triselenide to pulsed currents shows that the field-induced motion of the charge-density waves (CDWs) leaves them in long-lived metastable states in which, presumably, some distortion is stabilised by pinning. Evidence of this is provided by a reduction in Ohmic conductivity after current flows non-linearly through a specimen originally in thermal equilibrium, and by a transient increase in the non-linear conductivity on subsequent reversals of the current. A gradual increase in the non-linear conductivity during pulses applied repeatedly in the same sense is found to arise from a thermally-induced change in the strength of the pinning. The possible origin of this change is discussed.