PhD opening

PhD opening: Feshbach resonances between atoms and ions
University of Amsterdam, the Netherlands

In our group, we study mixtures of ultracold Li atoms that are interacting with crystals of trapped ions (see picture). Although atoms and ions have each been studied extensively in many labs in the world, mixing ultracold atoms with ions is a relatively novel field of physics [1]. Over the last years, numerous applications have been put forward for this system such as sympathetic cooling of ions by atoms, probing atomic systems with ions and using the system for quantum computation and quantum simulation. Unfortunately, however, nobody has managed so far to reach the low temperatures required for these ideas. We are about to change this. A careful analysis has shown that reaching the so-called quantum regime requires ion-atom combinations with a large mass ratio [2]. In our experiment, we use the species combination with the largest practically available mass ratio: Yb+-Li. We will very likely be the first group in the world to reach the quantum regime of atom-ion interactions.

Once there, we will answer an intriguing question: Do magneto-molecular, or Feshbach resonances, exist between atoms and ions? Such resonances play a pivotal role in neutral atomic system for the purpose of tuning the atom-atom interactions and find wide spread application in studying atomic quantum many-body systems [3] and in quantum simulation. They allow the experimentalist to switch on or off the interactions between the particles at will. In ion-atom mixtures, their existence has been predicted [4], but they have not been observed so far as the required low temperatures have not been reached. Since we will very likely be the first group in the world to reach the quantum regime of atom-ion interactions, you could be the first person to observe Feshbach resonances between atoms and ions.

The observation of Feshbach resonances between atoms and ions will have a huge impact on atomic quantum physics as it will open up completely new possibilities in studying quantum many-body physics as well as in quantum technology. Possible applications include the tunable buffer-gas cooling of trapped ion quantum computers (currently the most accurate platform [5]), and quantum simulation of natural materials [6].

The research is funded by the Netherlands Organization for Scientific Research and will be performed in a fully operational experimental setup. It is expected to result in obtaining a PhD after 4 years.

For applying click here

For further information:
Rene Gerritsma                                                                                                                      University of Amsterdam
email:                                                                                                               web:


[1] Tomza et al., arXiv:1708.07832 (2017).                          [4] M. Tomza et al., PRA 91, 042706 (2015).
[2] Cetina et al., PRL 109, 253201 (2012).                             [5] PRL  117, 060504 and 060505 (2016).
[3] C. Chin et al., Rev. Mod. Phys. 82, 1225 (2010).          [6] U. Bissbort et al., PRL 111, 080501 (2013).