We discuss the nonlinear current of an interacting quantum dot coupled to
normal and superconducting reservoirs with applied voltage and temperature
differences. Due to the particle-hole symmetry introduced by the
superconducting lead, the pure (subgap) thermoelectric response vanishes.
However, we show that the Andreev bound states shift as the thermal gradient
increases. As a consequence, the I--V characteristic can be tuned with a
temperature bias if the system is simultaneously voltage biased. This is a
cross effect that occurs beyond linear response only. Furthermore, we emphasize
the role of quasiparticle tunneling processes in the generation of high
thermopower sensitivities.Comment: 6 pages, 5 figure
