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Electron-magnon coupling and nonlinear tunneling transport in magnetic nanoparticles

L. Michalak·C. M. Canali·V. G. Benza
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Abstract

We present a theory of single-electron tunneling transport through a ferromagnetic nanoparticle in which particle-hole excitations are coupled to spin collective modes. The model employed to describe the interaction between quasiparticles and collective excitations captures the salient features of a recent microscopic study. Our analysis of nonlinear quantum transport in the regime of weak coupling to the external electrodes is based on a rate-equation formalism for the nonequilibrium occupation probability of the nanoparticle many-body states. For strong electron-boson coupling, we find that the tunneling conductance as a function of bias voltage is characterized by a large and dense set of resonances. Their magnetic field dependence in the large-field regime is linear, with slopes of the same sign. Both features are in agreement with recent tunneling experiments.

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L. Michalak, C. M. Canali, V. G. Benza. 2007-01-23. Electron-magnon coupling and nonlinear tunneling transport in magnetic nanoparticles. https://doi.org/10.1103/physrevlett.97.096804

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