Molecule-Supported Magnetic-Atom Dimers on Au(111): Multiple Structures and Kondo Resonances

Magnetic-atom dimers on surface provide a powerful platform to study single spin interactions and qubit controls. They have been experimented on bare and thin-insulator-covered metallic surfaces, with strong and weak couplings between atoms and surfaces, respectively. If they are embedded in single molecules on surfaces, they may allow new geometric and electronic configurations as well as different coupling levels. But such system has rarely been studied. Here we report our scanning tunneling microscopy studies for molecule-supported magnetic-atom dimers on Au(111). Through on-surface reactions, Fe-Co dimers were embedded to porphyrin molecules in three different types. We observed zero-bias resonance in our scanning tunneling spectroscopy from one type with the Kondo temperature lower than Co-porphyrin molecules. Based on our density functional theory calculation results, atomic structures of three dimer structures were reproduced, and the observed Kondo behaviors were explained. Our study shows that the molecule supported magnetic-atom dimers can be a useful platform for studying spin physics and quantum information science.