Multiband superconductivity and the influence of electronic topological transitions (ETT) in the Mo-Re alloys

The superconductivity in the Mo-Re alloys has been discovered in the early 1960s as a strong coupling superconductor. The superconductivity in these alloys is quite interesting in the sense that the superconducting transition temperature TC in some of the β-phase Mo-Re alloys is about an order of magnitude higher than the constituent elements Mo and Re. Although, the material is quite old but the previous reports suggest that the reason for such a large enhancement in TC is not yet understood clearly. In a relatively recent literature, authors show the presence of electronic topological transitions (ETT) in these alloys. However, any correlation between the ETT and the superconducting properties of these alloys is yet to be established. With this background, we study the superconducting and
normal state properties of these alloys and got the evidences of two band superconductivity and the phonon assisted interband s-d scattering above 10 at. % Re in these alloys. We also complemented our results with the electronic structure study of these alloys performed through resonant photoemission spectroscopy (RPES) measurements.

In my seminar, I will discuss about the above mentioned results and will try to correlate the superconducting and normal state properties of these alloys with their electronic structure.