Tunable CDW and Superconductivity Phase Transitions in 1T-TaS$_2$ Thin Films through Gate-controlled Intercalation

1T-TaS$_2$ has a rich set of complex phases as a result of competition among multiple electronic orders in this layered material. The delicate balance among the various phases makes 1T-TaS$_2$ very sensitive to external modulations. Using PEO/LiClO$_4$ solid electrolyte as a medium between a gate electrode and the sample, we have successfully intercalated Li ions into 1T-TaS$_2$ thin flakes in a continuous and reversible way. This allows us to probe the interplay between CDW phases, Mott phase, and superconducting phase as the concentration of Lithium is varied. Apart from 1T-TaS$_2$, our method of controlled intercalation is a promising new technique which could be applied to other layered materials.