Search for induced surface superconductivity and defect structure in ion implanted topological insulators Bi$_{2}$Se$_{3}$, Bi$_{2}$Te$_{3}$ and Iron Chalcogenides Fe (Se/Te) Single Crystals

Topological superconductors represent a newly predicted phase of matter which is topologically distinct from conventional superconducting condensates of Cooper pairs. Electronic properties of Bi$_{2}$ X$_{3}$ topological insulators and Iron Chalcogenides FeX can be tuned by ion implantation. The defect structure of implanted Bi$_{2}$X$_{3}$ and FeX are studied using TEM analysis. This study presents an unprecedented route in inducing possible surface superconductivity in Bi$_{2}$Se$_{3}$, Bi$_{2}$Te$_{3}$, Fe (Se/Te) single crystals by ion implantation and the effect of ion implantation into spin-density wave (SDW) anomaly of Fe (Se/Te) single crystals studied using resistivity measurements. Due to the shallow implantation depth of the ions, the observed superconductivity is in principle confined to the surface or sub-surface level, and the normal state can be recovered by thermal annealing and annealing facilitates the tuning of the carrier concentrations in Bi$_{2}$X$_{3}$, FeX crystals to allow the study of surface transport associated with the topological surface states in Bi$_{2}$X$_{3}$.