Berlin 2008 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 3: Transport: Fluctuations and Noise
TT 3.3: Vortrag
Montag, 25. Februar 2008, 10:00–10:15, H 2053
Full Counting Statistics of a Quantum-Dot Aharonov-Bohm Interferometer — •Daniel Urban1,2, Rosario Fazio2,3, and Jürgen König1 — 1Ruhr-Universität Bochum — 2Scuola Normale Superiore, Pisa — 3International School for Advanced Studies, Trieste
The visibility of the interference signal in Aharonov-Bohm (AB) interferometers provides information about the coherence of transport channels. For instance, spin-flip processes in embedded quantum dots lead to partial destruction of the coherence [1] and thus reduction of the AB-oscillation amplitude. The occurrence of this effect depends on the dot occupation.
We perform a perturbation expansion of the Cumulant Generating Function [2] of an AB-Interferometer with embedded quantum dots in the regime of weak tunnel coupling. Different statistics are found for vanishing and infinite charging energy: Without interaction the interfering part of the statistics consists of non-resonant Poissonian processes with an even dependence on the AB-flux.
In the presence of strong interaction on the dot interaction gives rise to additional resonant processes with an odd flux dependence in non-equilibrium situations. In the regime where one dot-lead coupling is close to pinch-off, these processes consist of both single- and double-charge transfers.
[1] J. König and Y. Gefen, PRL 86, 3855 (2001).
[2] A. Braggio, J. König, and R. Fazio, PRL 96, 026805 (2006).