  We report low-temperature transport measurements performed on a planar
Nb-InGaAs-Nb proximity Josephson junction hosting a gate-defined lateral
quantum dot in the weak-link. We first study quasiparticle and Josephson
transport through the open junction, when all gates are grounded. When the
quantum dot is defined in the normal region by electrostatic depletion,
cotunneling spectroscopy allows us to directly probe the energy gap induced in
the two dimensional electron gas. Our data show good qualitative agreement with
a model describing resonant tunneling through an Anderson impurity connected to
superconducting electrodes. These results demonstrate the feasibility of
top-gated nanodevices based on a two-dimensional electron gas coupled to a
superconductor.
