  Magnetically coupled hybrid quantum systems enable robust quantum state
control through Landau-Zener transitions. Here, we show that an ultracold
atomic sample coupled to a nanomechanical resonator via oscillating magnetic
fields can be used to cool the resonator's mechanical motion, to measure the
mechanical temperature, and to enable entanglement of these mesoscopic objects.
We calculate the expected coupling for both permanent-magnet and
current-conducting nanostring resonators and describe how this hybridization is
attainable using recently developed fabrication techniques, including SiN
nanostrings and atom chips.
