Quantization of states and strain-induced transformation of charge-density waves in the quasi-one-dimensional conductor TaS3

We report studies of low-field conductivity, sigma, of nanosized samples of orthorhombic TaS3 as a function of strain, epsilon. The sigma(epsilon) curves show steplike changes associated with the "quantization" of the wave vector, q, of the charge-density wave. Based on the effect we have revealed the change of the q-vector with strain: its in-chain component (normalized by the reciprocal lattice constant) is found to increase with sample stretch. A similar q(epsilon) dependence results from the analysis of the sigma(epsilon) hysteresis for macroscopic samples. This means that the strain-induced anomalies cannot be explained by the transition of the CDW to fourfold commensurability with the pristine lattice (lock-in transition), as it was supposed earlier. We also discuss the metastable length states and the elastic anomalies in TaS3 in light of the observed q(epsilon) dependence.