Large optical tunability from charge density waves in 1T-TaS$_2$ under incoherent illumination

TL;DR

This paper demonstrates significant optical tunability in the charge density wave properties of 1T-TaS$_2$ induced by incoherent light, revealing a new way to control strongly correlated materials' phases.

Contribution

It introduces a novel method to control the phase of 1T-TaS$_2$ via light-induced rearrangement of charge density wave stacking, supported by experimental and theoretical analysis.

Findings

Large optical response tunability observed in 1T-TaS$_2$

Light-induced rearrangement of CDW stacking across layers

Interdomain CDW interaction as a control knob for phase manipulation

Abstract

Strongly correlated materials possess a complex energy landscape and host many interesting physical phenomena, including charge density waves (CDWs). CDWs have been observed and extensively studied in many materials since their first discovery in 1972. Yet, they present ample opportunities for discovery. Here, we report a large tunability in the optical response of a quasi-2D CDW material, 1T-TaS$_2$, upon incoherent light illumination at room temperature. We show that the observed tunability is a consequence of light-induced rearrangement of CDW stacking across the layers of 1T-TaS$_2$. Our model, based on this hypothesis, agrees reasonably well with experiments suggesting that the interdomain CDW interaction is a vital knob to control the phase of strongly correlated materials.