  We present a microscopic theory of transport through quantum dot set-ups
coupled to superconducting leads. We derive a master equation for the reduced
density matrix to lowest order in the tunneling Hamiltonian and focus on
quasiparticle tunneling. For high enough temperatures transport occurs in the
subgap region due to thermally excited quasiparticles, which can be used to
observe excited states of the system for low bias voltages. On the example of a
double quantum dot we show how subgap transport spectroscopy can be done.
Moreover, we use the single level quantum dot coupled to a normal and a
superconducting lead to give a possible explanation for the subgap features
observed in the experiments published in Appl. Phys. Lett. 95, 192103 (2009).
