Kondo effect in single-molecule magnet transistors

Abstract

We present a careful and thorough microscopic derivation of the Kondo Hamiltonian for single-molecule magnets (SMMs) transistors. When the molecule is strongly coupled to metallic leads, we show that by applying a transverse magnetic field it is possible to topologically induce or quench the Kondo effect in the conductance of a SMM with either an integer or a half-integer spin S>1/2. This topological Kondo effect is due to the Berry phase interference between multiple quantum tunneling paths of the spin. We calculate the renormalized Berry phase oscillations of the two Kondo peaks as a function of the transverse magnetic field by means of the poor man's scaling. In particular, we show that the Kondo exchange interaction between itinerant electrons in the leads and the SMM pseudo spin 1/2 depends crucially on the SMM spin selection rules for the addition and subtraction of an electron and can range from antiferromagnetic to ferromagnetic. We illustrate our findings with the SMM Ni4, which we propose as a possible candidate for the experimental observation of the conductance oscillations.

References in corpus (5)

• The numerical renormalization group method for quantum impurity systems
• Berry Phase Oscillations of the Kondo Effect in Single-Molecule Magnets
• Berry-phase blockade in single-molecule magnets
• Cotunneling and non-equilibrium magnetization in magnetic molecular monolayers
• Tunneling through magnetic molecules with arbitrary angle between easy axis and magnetic field

Cited by in corpus (2)

• Spin-bias driven magnetization reversal and nondestructive detection in a single molecular magnet
• Splitting of the Kondo resonance in anisotropic magnetic impurities on surfaces