Charge-Density-Wave Domain Depinning in Thin Films of Quasi-2D Tantalum Disulfide

The process of the charge-density-wave (CDW) depinning in quasi-2D materials such as 1T-TaS₂ is different from that in CDW materials with quasi-1D crystal structure. In 1T-TaS₂, the CDW depinning does not lead to the coherent sliding of the CDW with the corresponding nonlinear increase in current and appearance of the “narrow band noise”. The domain depinning in 1T-TaS₂ contributes to the current fluctuations, observed in the derivative I-Vs and low-frequency noise [1]. We investigated the temperature dependence of the current fluctuations in thin films of 1T-TaS₂. The thin films were exfoliated from the crystals grown by the chemical vapor transport method. The test structures for the measurements were fabricated using electron beam lithography. The current fluctuations appear prominently at the electric fields, which correspond to the transitions between various CDW condensate phases and at the onset of the depinning of the CDW domains. Our analysis suggests that the CDW domain depinning is induced by the electric field but facilitated by local heating. The CDW domains in 1T-TaS₂ can be electrically gated [2]. We will discuss the results on the effect of the electric gate on the threshold field for CDW domain depinning.