UC Riverside

The charge density wave (CDW) phase is a macroscopic quantum phenomenonwhere the periodic motion of atoms results in a new periodicity of the electron density. Here I present an investigation into the phase transitions and depinning of CDWs in single-crystal 1T-TaS2 / hBN heterostructure devices. It is known that 1T-TaS2 reveals multiple CDW phases below and above room temperature. In the nearly commensurate phase domain depinning occurs before the phase transition to the incommensurate phase. This study explores the differences in the depinning process of CDWs between quasi-2D materials and ”conventional” bulk CDW materials with quasi-1D motifs in their crystal structure. Domain depinning in quasi-2D 1T-TaS2 differs from that of conventional charge-density-wave materials, as it does not exhibit a noticeable abrupt increase in electric current. Rather, domain depinning occurs as current instabilities, revealed by the differential resistance before joule heating. The findings of this study contribute to the understanding of the behavior of CDWs in quasi-2D materials and aid in the optimization of device design.