Nano-infrared imaging of metal insulator transition in few-layer 1T-TaS₂

Abstract Among the family of transition metal dichalcogenides, 1T-TaS 2 stands out for several peculiar physical properties including a rich charge density wave phase diagram, quantum spin liquid candidacy and low temperature Mott insulator phase. As is thinned down to few-layer limit, interesting physics emerges in this quasi 2D material. Here, using scanning near-field optical microscopy, we perform spatial- temperature-dependent study on transitions thick microcrystal . We investigate encapsulated air-sensitive prepared under inert conditions cryogenic temperatures. find an abrupt metal-to-insulator limit. Our results provide new insight contrast previous transport studies thin where resistivity jump became undetectable, spatially resolved non-encapsulated samples which found gradual, inhomogeneous transition. A statistical analysis suggests bimodal high phases, that characteristic hysteresis preserved