ac-dc coupling and polarization for charge-density waves inTaS3

Abstract
Measurements of the charge-density-wave (CDW) response in TaS3 indicate that low-frequency polarization phenomena play an important role in the coupled ac-dc dynamics of this system. A simple phenomenological model, based on capacitive coupling, is proposed to explain the observed suppression of the dc threshold by a large-amplitude ac field, and also a phase shift of 90° for low generated difference frequencies in small-signal ac harmonic mixing below the dc threshold.