Properties of strained TaS samples in the state of charge density wave and in the normal state.

The uniaxial strain of quasi-one-dimensional conductor whiskers of orthorhombic TaS at a strain higher than ε ~ 0.8% leads to a sharp increase in the coherence of the properties of a charge density wave (CDW), which manifests itself in its motion in fields higher than threshold field E . During uniaxial elongation, TaS is shown to exhibit the following unusual properties even in weak fields: Peierls transition temperature T depends nonmonotonically on ε, one-dimensional fluctuations weaken near T , and the coherence length of a charge density increases at T < T . Investigations in fields higher than E show that the ultracoherent properties of CDW exist in a wide temperature range and are retained when temperature increases up to T . These properties of CDW make it possible to observe a sharp increase in E near T and an almost jumplike increase in E at T < 90 K. The increase in E at T is explained by a decrease in the coherence volume of CDW because of a fluctuational suppression of the Peierls gap. [ABSTRACT FROM AUTHOR]