Contributions of high-energy excitations to the linear and non-linear conduction near the Peierls transition

Abstract

Very thin samples of TaS3 (cross-section area ∼ 10-3 µm2) are found to demonstrate smearing of the I-V curves near the threshold field in the Peierls state. With approaching the Peierls transition temperature, TP, the smearing evolves into smooth growth of conductance from zero voltage, interpreted by us as the contribution of fluctuations to the non-linear conductance. The fluctuation contribution to the linear conductance near TP is identified independently. Both linear and non-linear contributions depend on temperature with close activation energies ∼ (2 - 4) x 103 K and apparently reveal the same process. We reject creep of the continuous charge-density waves (CDW) as an origin of the effect and show that it is spontaneous phase slippage that results to creep of the CDW. A model is proposed accounting for both the linear and non-linear parts of the fluctuation conduction up to TP