Two-orbital quantum many-body systems: from Kondo dynamics to mediated interactions

The interaction between localized spins and mobile fermions underlies the transport properties of a large variety of highly correlated materials.

Even a single localized spin impurity can dramatically influence the motion of many fermions in its surroundings, giving rise to one of the most remarkable phenomena in quantum many-body physics - the Kondo effect.

For a finite density of localized spins, the Kondo effect competes with non-local fermion-mediated Ruderman-Kittel-Kasuya-Yosida (RKKY) interactions, providing the driving force for many intriguing phenomena such as the unconventional superconductivity and the quantum critical behavior of heavy-fermion compounds.

Despite decades of investigations, fundamental issues remain concerning the dynamical and spatial properties of the Kondo effect, that are difficult to tackle in electron systems.

Further, a detailed understanding of the transition between the single-impurity Kondo problem and a system of interacting impurities is still missing. In OrbiDynaMIQs, I will develop a novel experimental platform for addressing such open questions.

Leveraging on recent progress in manipulating single atoms with optical tweezers, I will realize a versatile two-orbital quantum simulator based on ultracold fermionic ytterbium atoms.

I will focus on the spin-orbital dynamics of single and multiple localized impurities embedded in one- and two-dimensional itinerant fermion systems.

I will then investigate the emergence of RKKY interactions between localized spins, both in few-body and full lattice realizations, taking first steps in exploring a whole new range of spin-correlation phenomena in Kondo systems.

The proposed approach capitalizes on the strong interlink between quantum many-body physics and precision measurements with two-electron atoms, and on my experience at the confluence of these fields.

It will also facilitate studies of new two-orbital models with enlarged SU(N) symmetries beyond that of spin-1/2 electron systems.