Modulated Kondo screening along magnetic mirror twin boundaries in monolayer MoS2 on graphene

A many-body resonance emerges at the Fermi energy when an electron bath screens the magnetic moment of a half-filled impurity level. This Kondo effect, originally introduced to explain the abnormal resistivity behavior in bulk magnetic alloys, has been realized in many quantum systems over the past decades, such as quantum dots, quantum point contacts, nanowires, single-molecule transistors, heavy-fermion lattices, down to adsorbed single atoms. Here we describe a unique Kondo system which allows us to experimentally resolve the spectral function consisting of impurity levels and Kondo resonance in a large Kondo temperature range, as well as their spatial modulation. Our experimental Kondo system, based on a discrete half-filled quantum confined state within a MoS2 grain boundary, in conjunction with numerical renormalization group calculations, enables us to test the predictive power of the Anderson model which is the basis of the microscopic understanding of Kondo physics.