Towards magnetic trapping of molecules

The advent of buffer-gas loaded magnetic traps for atoms has opened the possibility of trapping paramagnetic molecules. We survey our results on the loading, trapping and spectroscopy of Eu atoms that demonstrated the technique. The principles governing molecular trapping considering in particular the O-2 and NO systems are outlined. The trapping of molecules should prove particularly useful in spectroscopy, especially ultra-high resolution spectroscopy that requires cold (slow), trapped (long interaction time) samples. Similar to cold atoms, cold molecules could be interrogated at a level of detail which is likely to provide new insights into their structure and interactions.