Strain-tuned vortex Majorana modes in Iron-based superconductor

Iron-based superconductors (FeSC) with topological bands have become one of the most promising platforms for studying Majorana quasiparticles, owing to their intrinsically large topological gap between the Majorana zero mode (MZMs) and other bound states. However, a practical implementation of braiding remains elusive due to the inhomogeneity of current compounds, and the lack of control over MZMs. In this talk, we present our work of controlling topological band structure and vortex MZMs for topological FeSC LiFeAs by in-situ strain method. By performing ARPES and STM on LiFeAs under strain, we realized the controlling of the topological-Dirac-band in LiFeAs, thus we are capable to induce the topological phase transition and find that the MZMs are corrodingly tuned inside vortices. Our work for the controllable Majorana modes by strain not only directly reveals the significant relationship between the vortex zero modes and superconducting topological surface state, but also should enlighten the applicable design of FeSCs device for the future MZM-braiding experiment.