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arXiv · 1807.08850

Cross-correlations in a quantum dot Cooper pair splitter with ferromagnetic leads

Piotr Trocha·Kacper Wrześniewski
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Abstract

We investigate Andreev transport through a quantum dot attached to two external ferromagnetic leads and one superconducting electrode. The transport properties of the system are studied by means of the real-time diagrammatic technique in the sequential tunneling regime. To distinguish various contributions to Andreev current we calculate the current cross-correlations, i.e. correlations between currents flowing through two junctions with normal leads. We analyze dependence of current cross-correlations on various parameters of the considered model, both in linear and nonlinear transport regimes. The processes and mechanisms leading to enhancement, suppression or sign change of current cross-correlations are examined and discussed. Interestingly, our results show that for specific transport regimes splitted Cooper pair results in two uncorrelated electrons. However, utilizing ferromagnetic leads instead of non-magnetic electrodes can result in positive current cross-correlations.

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Piotr Trocha, Kacper Wrześniewski. 2018-07-23. Cross-correlations in a quantum dot Cooper pair splitter with ferromagnetic leads. https://doi.org/10.1088/1361-648x/aacd24

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