Nonequilibrium dynamics of anisotropic large spins in the kondo regime: time-dependent numerical renormalization group analysis.
We investigate the time-dependent Kondo effect in a single-molecule magnet (SMM) strongly coupled to metallic electrodes. Describing the SMM by a Kondo model with large spin S>1/2, we analyze the underscreening of the local moment and the effect of anisotropy terms on the relaxation dynamics of the magnetization. Underscreening by single-channel Kondo processes leads to a logarithmically slow relaxation, while finite uniaxial anisotropy causes a saturation of the SMM's magnetization. Additional transverse anisotropy terms induce quantum spin tunneling and a pseudospin-1/2 Kondo effect sensitive to the spin parity.
Roosen
David
D
Institut für Theoretische Physik, Johann Wolfgang Goethe-Universität, 60438 Frankfurt/Main, Germany.
Wegewijs
Maarten R
MR
Hofstetter
Walter
W