Ion irradiation of iron chalcogenide superconducting films

Iron-chalcogenide FeSe x Te1-x (Fe(Se,Te)) superconductors have attracted a great deal of interest in both fundamental physics and potential applications. While Majorana zero-modes hosted by the Fe(Se,Te) superconductors hold great promise for topological quantum computing, low-anisotropy and very high upper critical fields make Fe(Se,Te) an excellent candidate for high-magnetic-field and energy applications. Recently, we demonstrated a route for creating structural defects by ion irradiation in Fe(Se,Te) films, leading to strong flux pinning. Ion irradiation into Fe(Se,Te) films significantly improved the critical current density J c over a wide field range and for all orientations with respect to magnetic field. In particular, a robust enhancement of critical temperature T c and J c was realized simultaneously in the Fe(Se,Te) film irradiated with protons. Here, we provide a review of the ion-irradiated Fe(Se,Te) films, including the film growth and characteristics before and after irradiation, design of the irradiation process for different ion energies and species with irradiation simulations and experimental setups that are scalable for long-length Fe(Se,Te)-coated conductors.