Depinning of the Charge-Density Waves in Quasi-2D 1T-TaS2 Devices Operating at Room Temperature

TL;DR

This study demonstrates room-temperature depinning of charge-density waves in 1T-TaS2 thin-films using differential current-voltage and noise spectroscopy, revealing unique depinning behavior distinct from traditional quasi-1D materials.

Contribution

It introduces a novel method for detecting depinning thresholds in quasi-2D materials and highlights the distinct depinning characteristics of 1T-TaS2 at room temperature.

Findings

Depinning occurs without abrupt current increase.

Depinning fields are much larger than in quasi-1D materials.

Charge-density-wave current density is significantly lower than free carrier current density.

Abstract

We report on depinning of nearly-commensurate charge-density waves in 1T-TaS2 thin-films at room temperature. A combination of the differential current-voltage measurements with the low-frequency noise spectroscopy provide unambiguous means for detecting the depinning threshold field in quasi-2D materials. The depinning process in 1T-TaS2 is not accompanied by an observable abrupt increase in electric current - in striking contrast to depinning in the conventional charge-density-wave materials with quasi-1D crystal structure. We explained it by the fact that the current density from the charge-density waves in the 1T-TaS2 devices is orders of magnitude smaller than the current density of the free carriers available in the discommensuration network surrounding the commensurate charge-density-wave islands. The depinning fields in 1T-TaS2 thin-film devices are several orders of magnitude larger than those in quasi-1D van der Waals materials. Obtained results are important for the proposed applications of the charge-density-wave devices in electronics.