Current fluctuations and domain depinning in quasi-two-dimensional charge-density-wave 1T-TaS2 thin films

Abstract

We investigated the temperature dependence of the current fluctuations in thin films of the quasi-two-dimensional 1T-TaS2 van der Waals material. The current fluctuations, determined from the derivative current–voltage characteristics of two-terminal 1T-TaS2 devices, appear prominently at the electric fields that correspond to the transitions between various charge-density-wave macroscopic quantum condensate phases and at the onset of the depinning of the charge density wave domains. The depinning threshold field, ED, monotonically increases with decreasing temperature within the nearly commensurate charge-density-wave phase. The ED value increases with the decreasing 1T-TaS2 film thickness, revealing the surface pinning of the charge density waves. Our analysis suggests that the domain depinning is pronounced in the nearly commensurate phase. It is induced by the electric field but facilitated by local heating. The measured trends for ED of the domain depinning are important for understanding the physics of charge density waves in quasi-two-dimensional crystals and for developing electronic devices based on this type of quantum materials.