A low-temperature scanning tunneling microscope is used to perform spin-excitations on individual magnetic transition metal atoms when placed onto a crystal surface. By following these excitations... Show moreA low-temperature scanning tunneling microscope is used to perform spin-excitations on individual magnetic transition metal atoms when placed onto a crystal surface. By following these excitations while applying external magnetic fields the precise influence of the anisotropic crystal field on the spins of iron and manganese atoms is investigated. Similar experiments on an individual cobalt atom lead to the observation of a Kondo resonance. This can be explained by showing that the crystal field reduces the 3/2 spin state to an effective spin-1/2 Kramers doublet. The influence of the local environment (i.e. magnetic field, crystal field anisotropy and spin-coupling to neighboring atoms) on the characteristics of the Kondo resonance is studied. Show less
