Kondo Screening and Coupling of Spin States on Graphene Nanoribbon

Exploring the spatial dependence of mediated exchange interactions is very useful to understand the mechanism of magnetic ordering and coupling of spin states. The confined structure and low spin‐decoherence channel of 7‐armchair graphene nanoribbon (7‐AGNR) offer a suitable platform to partially isolate the effect of substrate and visualize the competition between exchange interactions and Kondo screening. Herein, we use scanning tunneling methods to map the spatial dependence of local density of states between two unpassivated sites across the terminus of 7‐AGNR. A well‐pronounced pair of delocalized Kondo resonances was observed which gradually decay away from the scattering centers but still visible at any point along the line profile. This ubiquitous presence of the Kondo effect indicates mediated exchange interactions that may lead to magnetic ordering or exotic coupling between spin states. Although thermal decoherence weakens the signal intensity, temperature dependence shows that the interaction effects remain detectable at a relatively high temperature of 14 K. As the coupling strength of the two delocalized moments could be tuned by an electric field, this system offers great potential for applications in devices employing quantum information processing.