  A quantum dot weakly coupled to two normal metal leads exhibits resonant
transmission when one of the dot energy levels lies within the applied bias
window. But when the quantum dot is sidecoupled to the transport channel,
transmission in the channel is suppressed when a dot energy lies in the bias
window. A steady current can also be driven in a transport channel by
connecting it to superconducting reservoirs and applying a Josephson phase
difference instead of a voltage bias. An interesting question is to investigate
the transport across quantum dot connected to two superconductors maintained at
a superconducting phase difference. To incorporate the geometry where quantum
dot is sidecoupled, we consider a quantum dot with two sites connected to the
superconductors in two geometrical configurations: (A) the one where both the
sites are in the transport channel and (B) the other where only one site is in
the transport channel and the second site sidecoupled. We find that both the
configurations show resonant transmission for Josephson current and give
qualitatively same result when the onsite energies of the two sites in the dot
are equal. The two configurations exhibit distinct Josephson current
characteristics when the onsite energies of the two sites are equal in
magnitude and opposite in sign. We understand the obtained results. The systems
studied are within the reach of current experiments.
