Regensburg 2007 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 28: Transport - Poster Session
TT 28.16: Poster
Donnerstag, 29. März 2007, 14:00–17:45, Poster A
Super-Poissonian current noise in coupled single-electron transistors — •Björn Kubala1, Göran Johansson2, and Jürgen König1 — 1TP III, Ruhr-Universität Bochum, Germany — 2MC2, Chalmers University Göteborg, Sweden
Non-Poissonian noise has been explored theoretically and experimentally in a variety of systems. Here, we investigate zero-frequency noise in networks of coupled single-electron transistors (SETs) within a real-time diagrammatic theory [1]. We calculate noise including all contributions up to second order in the coupling strength, whereby incorporating sequential and standard cotunneling processes, but also renormalization processes and cotunneling involving several transistor islands. For a single SET we reproduce results of orthodox and cotunneling theories and find the familiar suppression of noise in double-barrier systems.
The capacitative coupling of two SETs in parallel, however, permits an investigation of novel correlation effects, e.g., a bunching of electrons also found in semiconductor systems [2]. We identify a number of different mechanisms causing super-Poissonian noise, which could be experimentally investigated in coupled SETs.
[1] B. Kubala, G. Johansson, and J. König, Phys. Rev. B 73, 165316 (2006).
[2] S. S. Safonov, A. K. Savchenko, D. A. Bagrets, O. N. Jouravlev, Yu. V. Nazarov, E. H. Linfield, and D. A. Ritchie, Phys. Rev. Lett. 91, 136801 (2003).