Laterally confined metal-to-insulator and quasi-two-dimensional–to–two-dimensional transition by focused Rb intercalation of1T-TaS2

Submicrometer lateral control of the surface electronic properties of the layered correlated electron material $1T$-TaS${}_{2}$ is achieved in situ by focused Rb deposition at room temperature and verified using photoemission microscopy and spectroscopy, as well as scanning tunneling microscopy. The laterally confined Rb deposition results in the formation of a dense pattern of insulating islands in a metallic background. The local metal-to-insulator transitions are driven by Rb intercalation and accompanied by a change of the dimensionality of the surface electronic structure from quasi-2D to essentially 2D. The results establish the feasibility of spatially controlled in situ intercalation of layered materials.