A new experimental apparatus for exploring the SU(N) Fermi-Hubbard model

The Fermi-Hubbard model is a cornerstone model of condensed matter physics. Extending this model to the SU(N) symmetric case promises new exotic magnetic phases beyond the limits of natural materials. The behavior of such systems is hard to predict theoretically. Experimentally however, the SU(N) Fermi-Hubbard model can be realized and studied with the fermionic isotopes of alkaline-earth atoms, where the interactions are SU(N) symmetric, i.e., independent of the internal state of the atom.

 

In our experiment, we use ultracold fermionic strontium atoms which have with N = 10 the largest SU(N) symmetry available to atomic physics. Making use of the narrow red transition of strontium, we reach few μK temperatures, enabling direct loading into an optical dipole trap for further evaporative cooling. Once we reach quantum degeneracy, we plan to load the strontium atoms into an optical lattice, operating at a magic wavelength. To probe the system, e.g., its ground state, we will install a high-NA objective, enabling us to image with single atom and single site resolution. Making use of the clock transition to spin-dependently shelve the atoms in the clock state, we will also be able to extract the spin structure of the system.

In my talk I will present the design of the machine and the current status of the experiment.