MT-MOT: a Hybrid Magnetic Trap / Magneto-Optical Trap

Abstract

Arrays of cold atoms in magnetic traps have been implemented for use in quantum simulation, metrology, and ultracold chemistry. The scope of all of these fields could be greatly enhanced with cold and ultracold molecules. Cooling and trapping molecules, however, poses unique challenges compared to atoms. Sympathetic cooling, whereby molecules are cooled via collisions with ultracold atoms, will be a key technique for achieving the required densities and temperatures.

Towards this end, the Carty group in Durham has constructed a moving-trap Zeeman decelerator (`MTZD'), based on the same operating principles as a conventional Zeeman decelerator but producing a truly dynamic three-dimensional trapping potential. We have begun to characterise the decelerator with metastable argon, showing 3D guiding and deceleration, and intend to move to molecules in the near future.

In the longer term the decelerator is intended to load a magnetic trap. Presented here are the findings from preliminary work to design a hybrid magnetic trap with magneto-optical trap capability, or `MT-MOT'. The MT-MOT comprises six toroidal permanent magnets plus switchable electromagnetic coils. We have performed simulations to determine the feasibility of co-loading lithium atoms and calcium hydride molecules. Some consideration of loss mechanisms and likely trap lifetimes are discussed.