Spin-polarized transport through weakly coupled double quantum dots in the Coulomb-blockade regime

Abstract

We analyze cotunneling transport through two quantum dots in series weakly coupled to external ferromagnetic leads. In the Coulomb blockade regime the electric current flows due to third-order tunneling, while the second-order single-barrier processes have indirect impact on the current by changing the occupation probabilities of the double dot system. We predict a zero-bias maximum in the differential conductance, whose magnitude is conditioned by the value of the inter-dot Coulomb interaction. This maximum is present in both magnetic configurations of the system and results from asymmetry in cotunneling through different virtual states. Furthermore, we show that tunnel magnetoresistance exhibits a distinctively different behavior depending on temperature, being rather independent of the value of inter-dot correlation. Moreover, we find negative TMR in some range of the bias voltage.

9 pages, 7 figures, accepted in Phys. Rev. B

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Cited by in corpus (11)

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• Waiting time distribution revealing the internal spin dynamics in a double quantum dot
• Capacitively coupled double quantum dot system in the Kondo regime
• Charge and spin configurations in the coupled quantum dots with Coulomb correlations induced by tunneling current
• Influence of spin waves on transport through a quantum-dot spin valve
• Pauli spin blockade with site-dependent g-tensors and spin-polarized leads
• Study of couplings effect on the performance of a spin-current diode: Nonequilibrium Green's function based model
• Diagnostics of many-particle electronic states from non-stationary currents and residual charge
• Revealing the internal spin dynamics in a double quantum dot by periodic voltage modulation