Frequency dependent shear compliance of TaS3: Depinning relaxation spectra and search for a glass transition

Abstract At T ≈ 100 K, the magnitude of the shear compliance of TaS 3 increases by 25% with charge-density-wave (CDW) depinning by a dc voltage. We have measured the strain frequency dependence of the complex compliance ( j ) at different voltages, and fit it to distributions of Debye relaxation modes. The sensitivity of the compliance to the structure of the CDW suggests that it would also be sensitive to a glass transition. However, we find that both the real and imaginary parts of j are independent of frequency (within 1%) when the CDW remains pinned for 8 K j is also independent (0.1 %) of the frequency of small applied voltages, for which the dielectric constant varies greatly. Therefore, if there is a glass transition at these temperatures, these results imply that either it does not involve rearrangement of the CDW domain structure or that the elastic response time remains > l s for the pinned CDW.