For this, our team around PhD student Geram Hunanyan loaded cold atoms into an optical lattice., where the Bloch bands serve as the two-level system, and the bosonic mode is realized by a periodic oscillation of the optical trapping potential. Here the regime of deep strong coupling can be reached, where the coupling is not a perturbation any more, but dominates the dynamics. The results have been published in the journal Physical Review Research.
Gerams paper on the periodic quantum Rabi model published Ultracold Rubidium atoms in lattices simulate strongly coupled systems
The quantum Rabi model describes the coupling of a two-level system to a bosonic mode, one prominent example is an atom coupled to a light field. When the coupling gets stronger than the relevant energy scales of the atom and the light field new effects are expected, for example a collapse ad revival of the initial state. In optical systems, however, this regime is not achievable, but cold atoms can simulate this regime. This proposal, conceived together with our theory colleagues from Bilbao, has been tested successfully in our lab.
![Blick in die Vakuumkammer Blick in die Vakuumkammer](https://www.qo.uni-bonn.de/en/news/gerams-paper-zum-periodischen-quanten-rabi-modell-ist-publiziert/chamber_mot.jpg/@@images/image/leadimagesize)
Geram Hunanyan, Johannes Koch, Stefanie Moll, Enrique Rico, Enrique Solano und Martin Weitz
Periodic quantum Rabi model with cold atoms at deep strong coupling
Phys. Rev. Res. 6, 033023 (2024)
doi: 10.1103/PhysRevResearch.6.033023