Berlin 2012 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 13: Transport: Poster Session

TT 13.36: Poster

Montag, 26. März 2012, 15:00–19:00, Poster B

Light emission of tunneling electrons interacting via a localized plasmon — •Fei Xu¹, Federica Haupt², Cecilia Holmqvist¹, and Wolfgang Belzig¹ — ¹Fachbereich Physik, Universität Konstanz, Konstanz, Germany — ²Institut für Theorie der Statistischen Physik, RWTH Aachen, Aachen, Germany

Photon emission in electron tunneling can be related to current noise, which is an important tool to investigate quantum many-body effects in electron transport in a non-equilibrium mesoscopic conductor. Recent experiments on photon emission from atomic-size tunnel junctions formed by an STM tip and a metallic surface showed a considerable intensity of photons emitted with a frequency larger than the applied bias voltage ℏ ω> eV [1,2]. This is a fingerprint of electronic correlations involving electromagnetic plasmonic modes involving both the surface and the tip apex. We address the problem of this over-bias photon emission in terms of non-equilibrium current fluctuations in a conductor interacting with an electromagnetic environment. The latter can mediate tunneling processes, resulting in two electrons teaming up to cross the junction and emitting a single photon with energy higher than eV [3]. We model the plasmon resonance as an electrical RLC circuit and find that non-Gaussian noise yields one-photon emission with over-bias energy.
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