Spin-resolved spectra of Shiba multiplets from Mn impurities in MgB₂

We study the effect of magnetic Mn ions on the two-band superconductor MgB_2, and compute both the total and spin resolved scanning tunneling spectrum in the vicinity of the magnetic impurity. We show that when the internal structure of the Mn ion's d-shell is taken into account, multiple Shiba states appear in the spectrum. The presence of these multiplets could alter significantly the overall interpretation of local tunneling spectra for a wide range of superconducting hosts and magnetic impurities.