Energy Gap Measurements of K-doped, Co-doped, and P-doped Ba_(1-x)K_xFe₂As₂ Superconductors using Soft Point Contact Spectroscopy

Iron-based superconductors provide a new platform where multi-band superconductivity can be studied. Multiple energy gaps in these samples can be measured, depending on the way the crystal has been grown and how the tunneling directions are accessed through fabrication and the way electrical contacts are made. These energy gaps are anisotropic relative to the crystal lattice, with gaps sensitive to tunneling that is parallel or perpendicular to the c-axis of the lattice. In this presentation, we report our progress in ongoing measurements of the energy gaps of K-doped Ba_(1-x)K_xFe₂As₂, Co-doped and P-doped BaFe₂As₂. We report the observation of peaks and broad shoulders; some correlate well with existing data from literature while other new peaks are unexplained. These measurements were performed fully by undergraduates.