We have two experimental setups where we study of the effects of strong dipole-dipole interactions in systems of a few atoms:
- In the Rydberg project, we use arrays of optical tweezers, each containing a single Rb atom, and we induce strong interactions between the atoms by exciting them to Rydberg states. We have basically full control over the system: geometry and size of the array, exact number of atoms, strength of the interaction… With this platform, we are currently exploring the physics of spin Hamiltonians with up to 50 particles.
- In the Nanocloud project, we trap an adjustable number of Rb atoms (up to ~ 300) in the same microscopic dipole trap. The size of the cloud is comparable to the resonance wavelength of Rb and thus the optical response of the cloud features collective effects, due to the strong interaction between light-induced dipoles.