Cold chemistry with water
In cold, dilute gases such as the interstellar medium (ISM), the chemical reactions are dominated by ionic species since their net charge allows them to polarize and "capture" nearby neutrals for reactions. Tiangang and Gary have recently released the first results from their "ISM in a bottle" experiment, where they controlled the reactions of laser-cooled Be+ ions with neutral water molecules.
Surprisingly, despite the fact that this reaction is exothermic and allowed even at zero temperature, the reaction rate is suppressed compared to capture theory, an effect that our theory collaboratrs show is due to a bottleneck in the reaction pathway called a submerged barrier. Exotic effects of this type will be the target of study in this apparatus for the next phase of work.
Displacement phases appear in classical systems
Tony and Eliot (along with Paul Hamilton and Amar Vutha) have published a paper showing how an effect that is typically encountered in quantum systems (the "geometric phase" associated with the displacement operator) can be easily understood by looking at classical systems. They performed an experiment with classical optics to measure this phase and to help demonstrate its mechanism of action.
This paper may help to demystify the appearance of this effect, which often seems surprising to students when they first encounter it.
Scarlett Yu wins poster prize at ABRCMS
Scarlett Yu has been awarded a prize for her poster, "Stimulated Force for Optical Deceleration of Molecules," presented in the Engineering, Physics, and Mathematics category at the ABRCMS conference in Phoenix, Arizona.
This is a prestegious award for an undergraduate researcher, and Scarlett's stellar work on our cold polar molecule experiment continues to impress.
Congratulations to Scarlett!
Ion in the gyroscope trap
Adam West and Randy have trapped and crystallized Ba+ ions in the gyroscope for the first time.
They're working with 138Ba+, a stable isotope that does not have nuclear spin, and the internal state qubit will be encoded in Zeeman sublevels. This little fella wants nothing more than to start orbiting.
Radioactive quantum computing
Dave and Justin have recently trapped a synthetic isotope of barium and performed some preliminary spectroscopy of its structure. Singly-ionized barium-133 has an internal structure that makes it the envy of all trapped ion qubits -- the spin-1/2 nucleus makes it easy to initialize, the metastable D states are extremely long-lived for a process called "shelving," and the lasers are all in the friendly visible part of the spectrum.
This work is a collaboration with Eric Hudson, and you can learn more by reading the paper, which came out today in Physical Review Letters.