The machine in this photo is the experimental apparatus I work with every day, at the European Laboratory for Nonlinear Spectroscopy in Florence.
Among several complex devices, there is a vacuum chamber containing an ion trap that confines barium ions, and a second chamber with a magneto-optical trap for producing cold lithium clouds.
Ours is the first ion trapping experiment in Italy. About two years ago, we managed to trap the first barium ions and started experimenting. Now we have a very new system which allows us to arrange ions in two-dimensional crystals and study their structures.
Ion are atoms or molecules that carry an electric charge because they have lost or gained an electron. Our goal is to combine these ions with neutral atoms. Atoms and ions have longer interactions than those between atoms, and the idea is to use ions as impurities in a system of atoms. There are many phenomena that can be simulated with such a system, but the study of these interactions, and especially their application to quantum simulation (which is the use of a controlled quantum system to model large quantum systems like complex molecules) is still in its infancy.
These experiments are still amazing to me. It is incredible to be able to suspend individual atoms in a vacuum, and study them. For the pioneers of quantum physics, this was just a Gedankenexperiment, a thought experiment, whereas today we can actually do it. It is as if we now have an optical telescope that allows us to directly observe the surface of exoplanets 20 light years away— not technically impossible but unbelievable.
I am particularly proud of having brought the physics of trapped ions to Italy, where it was completely absent. I was born and raised in Sardinia, then went to university and started doing research in Rome, on quantum information with single photons. I did my PhD in Pisa working on Bose-Einstein condensates, then I moved to Cambridge, in the United Kingdom, where I worked on the first experiment that put together trapped ions with a Bose-Einstein condensate. I returned to Italy at the National Research Council, and in 2015 I was lucky enough to win both an ERC Starting Grant and a similar Italian grant, called SIR (Scientific Independence for Young Researchers).
We built our experiment thanks to these grants, and managed to do everything in Italy, which was a challenge. For example, it was very difficult to find someone who could build us the electrodes for the ion trap. Eventually we found a company in Imola that works with Ferrari on components of F1 cars. They helped us build these very small and complex devices, which require a whole production chain. We also patented an innovative laser design, which in turn earned an ERC Proof of Concept and other funds.
My research group is small but growing, and we aim at getting bigger. Something I had underestimated when I started doing research is how emotionally complex it sometimes is to have students counting on you. There are extremely talented young researchers who are giving their time, the most precious thing in the world, to follow ideas that you are suggesting. It is a responsibility that I feel very strongly. For me, to have achieved such good results so far is an achievement that involves the whole group.
