  We investigate charge transport through the junction between a niobium
superconductor and the edge of a two-dimensional electron-hole bilayer,
realized in an InAs/GaSb double quantum well. For the transparent interface
with a superconductor, we demonstrate that the junction resistance is
determined by the interlayer charge transfer near the interface. From an
analysis of experimental $I-V$ curves we conclude that the proximity induced
superconductivity efficiently couples electron and hole layers at low currents.
The critical current demonstrates periodic dependence on the in-plane magnetic
field, while it is monotonous for the field which is normal to the bilayer
plane.
