Optoelectrical Cooling of Polar Molecules

We present progress towards the experimental realization of optoelectrical cooling [1] which is widely applicable for producing samples of ultracold (<1 mK) polar molecules. This scheme exploits the interaction between trapped molecules and electric fields to remove energy, while a spontaneous vibrational decay removes entropy. The trap, a key element of this method, must not only provide long lifetimes, but also regions of variable homogenous electric fields, allowing the required addressing of transitions between individual rotational sublevels. We consider in detail the design of this microstructured electrical trap, where a trap depth of 1 K can be achieved. Careful patterning of the electrodes allows a suppression of trap losses by Majorana flips. [1] M. Zeppenfeld et al., Phys. Rev. A 80, 041401(R) (2009).