Strong tunneling and charge quantization in S-I-N Coulomb blockade structures

We study the charge of a small normal island connected by a tunnel junction to a superconducting lead. Unlike the N-I-N case, the steps of the Coulomb staircase remain sharp even if the conductance of the tunneling barrier exceeds e^2/h. One can observe the transition from sharp steps to the smeared ones by applying magnetic field to destroy the superconductivity.