  Polar molecules in selected quantum states can be guided, decelerated, and
trapped using electric fields created by microstructured electrodes on a chip.
Here we explore how transitions between two of these quantum states can be
induced while the molecules are on the chip. We use CO (a 3-Pi(1), v=0)
molecules, prepared in the J=1 rotational level, and induce the J=2 <-- J=1
rotational transition with narrow-band sub-THz (mm-wave) radiation. First, the
mm-wave source is characterized using CO molecules in a freely propagating
molecular beam, and both Rabi cycling and rapid adiabatic passage are examined.
Then, we demonstrate that the mm-wave radiation can be coupled to CO molecules
that are less than 50 micron above the chip. Finally, CO molecules are guided
in the J=1 level to the center of the chip where they are pumped to the J=2
level, recaptured, and guided off the chip.
