Comparison of elastic anomalies accompanyingcharge-density-wave depinning in TaS₃ and NbSe₃

Abstract

We compare the electric field and frequency dependence of the complex shear moduli of the charge-density-wave (CDW) conductors, TaS 3 and NbSe 3 . For both materials, the magnitudes of the shear moduli decrease when the CDW becomes depinned, but qualitatively different behaviors are observed for their internal friction. For TaS 3 the frequency dependence of the complex modulus seems to be well described in terms of relaxational dynamics, but this is not the case for NbSe 3 . The anomalies are discussed in terms of different models of CDW response to crystal strain.