Brian Odom April 23 Abstract

Adding molecular rotations to the quantum toolkit

Because of their rich internal structure, trapped molecules offer great potential for precision spectroscopy, quantum information processing, and ultracold and field-controlled chemistry. Obtaining control over the rotational quantum state of trapped molecules, a prerequisite for most applications, has however presented a significant challenge. Using a single spectrally filtered broadband laser, we have optically cooled trapped AlH+ molecules from room temperature to 4 Kelvins, corresponding to an increase in ground rotational-vibrational state population from 3% to 95%. We anticipate that the cooling timescale can be reduced from 100 milliseconds to a few microseconds and that the cooling efficiency can also be improved. Trapped AlH+ is a good candidate for future work on quantum-controlled chemistry, coherent control and entanglement of rotational quantum states, non-destructive single-molecule state readout by fluorescence, single-molecule spectroscopy, and searches for time-variations of the electron-proton mass ratio.