  We study a quantum ladder of interacting fermions with coupled s and p
orbitals. Such a model describes dipolar molecules or atoms loaded into a
double-well optical lattice, dipole moments being aligned by an external field.
The two orbital components have distinct hoppings. The tunneling between them
is equivalent to a partial Rashba spin-orbital coupling when the orbital space
(s, p) is identified as spanned by pseudo-spin 1/2 states. A rich phase
diagram, including incommensurate orbital density wave, pair density wave and
other exotic superconducting phases, is proposed with bosonization analysis. In
particular, superconductivity is found in the repulsive regime.
