Kondo anomalies in magnetic nanocontacts from first principles

A realistic calculation of electron transport through magnetic nanocontacts should connect together DFT based electronic structure with many body methods like NRG. We recently moved a first step in this direction [1,2]. Identifying symmetry-dictated conduction channels, we calculate first the DFT channel- and spin-dependent impurity scattering phase shifts; then build an Anderson model whose symmetry and parameters are forced to reproduce at the Hartree Fock level the phase shifts; and finally solve the Anderson model by NRG. This yields much more than just the Kondo temperature. As exemplified by a Ni impurity in a Au nanocontact, we uncover the orbital origin the Fano interference in the predicted zero bias Kondo anomalies; the origin of their large structural dependence; and the likely occurrence of the so far ignored ``ferro'' Kondo effect. We are presently extending calculations to other nanocontacts including magnetic impurities on surfaces and nanotubes.\\[4pt] [1] P. Lucignano et al., Nat. Mat. 8, 563 (2009).