Regensburg 2007 – scientific programme

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TT: Fachverband Tiefe Temperaturen

TT 23: Nanoelectronics II - Spintronics and Magnetotransport

TT 23.11: Talk

Thursday, March 29, 2007, 12:15–12:30, H19

Electron transport in quantum dots in the spin blockade regime — Carlos Lopez-Monis¹, Maria Busl^1,2, Jesus Inarrea^1,3, Gianaurelio Cuniberti², and •Gloria Platero¹ — ¹ICMM, CSIC, Cantoblanco, E-28049 Madrid — ²Institut für Theoretische Physik, Universität Regensburg, D-93040 Regensburg — ³Escuela Politecnica Superior, Universidad Carlos III, E-28911 Madrid

Recent experiments of transport through two weakly coupled quantum dots [1] show finite currents in the spin blockade region which is attributed to the hyperfine interaction between electronic and spin nuclei. We analyze the electronic spin transport through different quantum dot configurations in the regime where spin blockade occurs. We include in our description phonon-mediated hyperfine interaction between the electron and spin nuclei through the Overhauser effect, as the main source of spin-flip. Our model consists on rate equations for the electronic states occupations and nuclei spin polarizations which are treated in a self-consistent way [2]. We discuss the current as a function of an external magnetic field, where singlet and triplet inter-dot state crossings occur.

[1] K. Ono et al., Science 297 1313 (2002); K. Ono et al., Phys. Rev. Lett. 92, 256803 (2004).

[2] J. Inarrea et al., cond-mat/0609323; J. Inarrea et al., Physica Status Solidi (a), 203, 6 1148 (2006).