Monopole supersymmetries and the Biedenharn operator

The hidden supersymmetry of the monopole found by De Jonghe et al. is generalized to a spin 12 particle in the combined field of a Dirac monopole plus a λ2/r2 potential [considered before by DʹHoker and Vinet], and related to the operator introduced by Biedenharn a long time ago in solving the Dirac–Coulomb problem. Explicit solutions are obtained by diagonalizing the Biedenharn operator.