We describe a superconducting Casimir apparatus inspired by a recently
proposed setup involving magnetic surfaces [G. Bimonte, Phys. Rev. Lett. {\bf
112}, 240401 (2014)]. The present setup consists of a superconducting Nb sphere
and a flat gold plate including in its interior a superconducting Nb strip. The
experimental scheme involves a differential measurement of the Casimir force at
a point of the gold plate above the Nb strip and away from from it. We show
that similar to the previous setup, the superconducting system considered here
implies widely different modulations of the Casimir force, depending on whether
the thermal force is computed using the Drude or the plasma model, thus paving
the way to an unambiguous discrimination between these alternative
prescriptions.Comment: 9 pages, 4 figures, invited contribution to a special issue on
Casimir Forces of J. Phys. Cond. mat
