Using Molecular States to Probe Spin Properties of Single Molecules

Here, we discuss the enhancement of the scanning tunneling microscope (STM) through the functionalization of the STM tip with single molecules. Using a sub-Kelvin STM, we observe that a magnetic molecule can be reproducibly transferred from the surface to the tip and forms a Kondo state. This many-body resonance undergoes exchange splitting in the proximity of another magnetic molecule adsorbed on the substrate surface and exhibits effects of spin polarization in the mutual inelastic conductance. The Kondo tip influences the inelastic spin-flip excitation in the magnetic molecule and a hybrid Kondo-spin excitation state emerges. These results reveal magnetic sensing between a many-body resonance and discrete excitations between two magnetic molecules