Paper detail

Pathway to Kondo physics in ytterbium atom chains with repulsive spin impurities

The Kondo effect is a paradigmatic model of strongly-correlated physics, where a magnetic impurity forms a many-body singlet with a fermionic environment. Cold gases of ytterbium (Yb) atoms have been proposed to be an ideal platform to study the Kondo effect since different internal states of the atom can be used to create both the impurity and the fermionic environment. In Yb gases, however, the atomic impurity interacts with the fermionic environment both through magnetic and potential scattering. These two scattering mechanisms counteract one another, raising the question of how robust Kondo screening remains. Here, we show that potential scattering can quench the Kondo screening in one-dimensional Yb gases; yet, strikingly, Kondo physics survives this quench in well-defined regimes. Combining analytical renormalization-group theory for a Luttinger liquid with density matrix renormalization group (DMRG) simulations, we identify a transition from a strongly- to a weakly-entangled impurity as potential scattering is increased. The two approaches show excellent agreement concerning the stability of Kondo physics throughout the different parameter regimes considered. Our results provide a quantitative criterion for the emergence of Kondo screening in one-dimensional Yb gases and delineate experimentally accessible regimes for its realization in cold-atom platforms.