In‐Plane Chirality Control of a Charge Density Wave by Means of Shear Stress

Abstract The transition metal dichalcogenide 1T‐TaS 2 exhibits a Charge Density Wave (CDW) with in‐plane chirality. Due to the rich phase diagram, the Ferro‐Rotational Order (FRO) can be tuned by external stimuli. The FRO is studied by Angle‐Resolved Photoelectron Spectroscopy (ARPES), Raman spectroscopy, and Selected Area Electron Diffraction (SAED). The in‐plane chirality of the CDW is lost at the transition from Nearly‐Commensurate (NC) to In‐Commensurate (IC) phase and can be controlled by applying shear stress to the sample while cooling it through the transition from IC‐CDW to NC‐CDW. Based on these observations, a protocol is proposed to achieve reliable, non‐volatile state switching of the FRO configuration in 1T‐TaS 2 bulk crystals. These results pave the way for new functional devices in which in‐plane chirality can be set on demand.