Engineering correlations with ultracold atoms: Kondo physics and

non-equilibrium dynamics

Dr. Johannes Bauer

Department of Physics, Harvard University, USA

In recent years significant progress has been made in studying correlated many-body phases with ultracold atoms. Here, we propose a realization of Kondo physics. It is based on a Fermi sea of two different hyperfine states of one atom species forming bound states with a different species, which is a spatially confined in a trapping potential. We show that

different situations displaying Kondo physics can be realized when Feshbach resonances between the species are tuned by a magnetic field and the trapping frequency is varied. We illustrate that a mixture of 40K and 23Na atoms has suitable properties to generate a Kondo-correlated state. We compute the characteristic radio frequency signals expected to be observed in experiments. We also demonstrate how in the proposed setup open question concerning the spatial extent and the formation of a Kondo cloud can be examined by spectroscopic tools available in quantum optics. We also study a system of repulsive fermions in a lattice, where the interaction is ramped up to values, where the system is expected to order antiferromagnetically in equilibrium. We identify relevant time scales and heuristically argue that an instability from a prethermalized state can

occur. We also extend the analysis to time dependent non-equilibrium calculations for the response function in the Keldysh formalism.