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

At T ≈ 100 K, the magnitude of the shear compliance of TaS3 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 < T < 70 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.