Electrical Gating of the Charge-Density-Wave Phases in Quasi-2D h-BN/1T-TaS$_2$ Devices

TL;DR

This study demonstrates electrical control over charge-density-wave phases in h-BN capped 1T-TaS2 devices, enabling potential room-temperature memory applications through gate-induced phase transitions.

Contribution

It reveals electric-field modulation of charge-density-wave phases in 1T-TaS2 heterostructures, a novel approach for phase control in 2D materials.

Findings

Gate bias shifts charge-density-wave hysteresis.

Abrupt current spikes indicate electric rather than thermal effects.

Charge-density-wave phases are stable at room temperature.

Abstract

We report on electrical gating of the charge-density-wave phases and current in h-BN capped three-terminal 1T-TaS$_2$ heterostructure devices. It is demonstrated that the application of a gate bias can shift the source-drain current-voltage hysteresis associated with the transition between the nearly commensurate and incommensurate charge-density wave phases. The evolution of the hysteresis and the presence of abrupt spikes in the current while sweeping the gate voltage suggest that the effect is electrical rather than self-heating. We attribute the gating to an electric-field effect on the commensurate charge-density-wave domains in the atomic planes near the gate dielectric. The transition between the nearly commensurate and incommensurate charge-density-wave phases can be induced by both the source-drain current and the electrostatic gate. Since the charge-density-wave phases are persistent in 1T-TaS2 at room temperature, one can envision memory applications of such devices when scaled down to the dimensions of individual commensurate domains and few-atomic plane thicknesses.