Magnetic field modulated Kondo effect in a single-magnetic-ion molecule

We study numerically the low-temperature electronic transport properties of a single-ion magnet with uniaxial and transverse spin anisotropies. We find clear signatures of a Kondo effect caused by the presence of a transverse (zero-field) anisotropy in the molecule. Upon applying a transverse magnetic field to the single-ion magnet, we observe oscillations of the Kondo effect due to the presence of diabolical (degeneracy) points of the energy spectrum of the molecule caused by a geometrical phase interference effects similar to those observed in the quantum tunneling of multi-ion molecular nanomagnets. The field-induced lifting of the ground state degeneracy competes with the interference modulation, resulting in some cases in a suppression of the Kondo peak.