Localized magnetic moments with tunable spin exchange in a gas of ultracold fermions

TL;DR

This paper demonstrates the experimental creation of a state-dependent lattice with tunable spin exchange in ultracold fermionic gases, modeling Kondo physics and revealing resonant control of magnetic interactions.

Contribution

It introduces a novel state-dependent lattice for fermionic gases with tunable spin exchange, enabling simulation of Kondo-like interactions in a controlled quantum system.

Findings

Realization of a state-dependent lattice with strong interorbital spin exchange.

Observation of resonant tuning of spin exchange via on-site confinement.

Modeling of Kondo Hamiltonian interactions in ultracold fermions.

Abstract

We report on the experimental realization of a state-dependent lattice for a two-orbital fermionic quantum gas with strong interorbital spin exchange. In our state-dependent lattice, the ground and metastable excited electronic states of $^{173}$Yb take the roles of itinerant and localized magnetic moments, respectively. Repulsive on-site interactions in conjunction with the tunnel mobility lead to spin exchange between mobile and localized particles, modeling the coupling term in the well-known Kondo Hamiltonian. In addition, we find that this exchange process can be tuned resonantly by varying the on-site confinement. We attribute this to a resonant coupling to center-of-mass excited bound states of one interorbital scattering channel.