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Inelatic cotunneling current and shot noise of an interacting quantum dot with ferromagnetic correlations

Bing Dong·X. L. Lei·Norman J. M. Horing
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Abstract

We explore inelastic cotunneling through a strongly Coulomb-blockaded quantum dot attached to two ferromagnetic leads in the weak coupling limit using a generic quantum Langevin equation approach. We first develop a Bloch-type equation microscopically to describe the cotunneling-induced spin relaxation dynamics, and then develop explicit analytical expressions for the local magnetization, current, and its fluctuations. On this basis, we predict a novel zero-bias anomaly of the differential conductance in the absence of a magnetic field for the anti-parallel configuration, and asymmetric peak splitting in a magnetic field. Also, for the same system with large polarization, we find a negative zero-frequency differential shot noise in the low positive bias-voltage region. All these effects are ascribed to rapid spin-reversal due to underlying spin-flip cotunneling.

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Bing Dong, X. L. Lei, Norman J. M. Horing. 2006-11-23. Inelatic cotunneling current and shot noise of an interacting quantum dot with ferromagnetic correlations. https://arxiv.org/abs/cond-mat/0509098

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