The realization of an innovative experimental apparatus was made possible by the development of novel strategies for the realization of several fundamental and technical processes that are at the base of the experiment.
These advancements are or will be soon reported in scientific publications, which will be relevant not only for the atom-ion community, but for a large portion of the wide atomic physics community. These achievements are mainly five.
1. A new ion trap for confining charged particles by using a combination of an electrical static field and an optical field. This new trap does not make use of radiofrequencies, and it therefore lifts the main limitation that has so far made it impossible to produce ultracold atom-ion mixtures, i.e. to bring atoms and ions together to temperatures at which the mixture undergoes a quantum coherent evolution. The techical details of the trap, and of its simulated behaviors are available in a scientific publication: Perego et al. Appl. Sci. 2020, 10(7), 2222
2. A new electronic and software control system, based on programmable FPGA chips. While commercial electronic boards typically execute pre-determined temporal sequences of electric signals, therefore not allowing any action on the electrical outputs while the sequence is executed, the new control software and electronic boards designed by the research team make this possible. As a result, the machine-time of the experimental setup can be optimized so that two experiments can be performed at the same time. This new control system was reported in a publication in Review of Scientific Instruments (Perego et al. Rev. Sci. Instrum. 89, 113116 (2018) ).
3. A new RF drive providing the electric signal to operate a Paul trap. Paul traps are the most commonly used traps for confining charged particles. In order to function, the electrodes of the trap must be fed with an intense RF electric signal. Typically, this is realized either by using large amplifiers, or by implementing bulky resonant circuits. Instead, we have developed a new, compact and inexpensive RF drive that is confined in a single electronic board (smaller than a hand), based on a low-noise amplifier on on low-losses ferrites used to realize highly performing inductors. This new RF drive was reported in a publication in Review of Scientific Instruments (Detti et al. Rev. Sci. Instrum. 90, 023201 (2019) ).
4. A new laser source, made by a diode laser in an extended cavity configuration. The new laser source solves existing problems of instability that affect similar sources, and allows us to realize laser sources for atomic and molecular spectroscopy in a cheap and reliable way. A patent is currently pending on this novel laser design, and a scientific publication is under preparation.
5. We theoretically investigated a new strategy for realizing one-photon Li sideband cooling, with a scheme that provides a simplification with respect to the existing schemes for Li sideband cooling, which are based on the action of two lasers. The theoretical study was performed by the PI and by one member of the research team, who was awarded the best poster prize at the course 206 of the Enrico Fermi Physics School in Varenna, Italy. The prize consisted in the right of publishing a short article in the School book. The article, which has been recently submitted, is available online (arXiv:1912.08104).
