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HL: Fachverband Halbleiterphysik
HL 48: Poster 2
HL 48.67: Poster
Donnerstag, 26. März 2009, 15:00–17:30, P2
Non-local control of cotunneling currents in a two-impurity Kondo system — •Daniel Tutuc1, Matthias Reinwald2, Werner Wegscheider2, and Rolf J. Haug1 — 1Institut für Festkörperphysik, Leibniz Universität Hannover, 30167 Hannover — 2Angewandte und Experimentelle Physik, Universität Regensburg, 93040 Regensburg
We present measurements on non-local cotunneling current control in a system of two magnetic impurities - realized by two quantum dots - coupled through an open conducting region, which can be attributed to the influence of the effective interaction between magnetic moments [1-3]. The sample consists of two lateral quantum dots connected via an open region of about 300 nm, created by Local Anodic Oxidation with an AFM on a GaAs/AlGaAs heterostructure with a 2DEG 34nm beneath the surface. The measurements have been performed with the standard lock-in technique, in a dilution refrigerator, at about 100 mK electron temperature. We investigate the effective interaction between magnetic moments in dependence on the dot coupling to the central region and on an in-plane magnetic field. The interaction between the magnetic moments is destroyed for weak dot coupling to the central region and for magnetic fields higher than 8T.
[1] N. J. Craig et al., Science 304, 565 (2004)
[2] P. Simon, et al., Phys. Rev. Lett. 94, 086602 (2005)
[3] M. G. Vavilov and L. I. Glazman, Phys. Rev. Lett. 94, 086805 (2005)