Hannover 2013 – scientific programme

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Q: Fachverband Quantenoptik und Photonik

Q 35: Poster I

Q 35.63: Poster

Tuesday, March 19, 2013, 16:00–18:30, Empore Lichthof

Analysis of electron-wave decoherence near a semiconducting surface — Regine Frank, •Thimo Böhl, Henrike Prochel, Alexander Rembold, and Alexander Stibor — Physikalisches Institut, Tübingen, Deutschland

Dissipation and localization effects lead to decoherence. Novel quantum devices, such as hybrid quantum systems, exist in the transition region between a pure quantum state and a classical object. Understanding the strength of distinct decoherence mechanisms is still a challenge, which needs to be solved to realize new technical applications in the quantum regime. Here we describe an experiment were electron wave decoherence is observed in a biprism interferometer in the vicinity of a semiconducting plate [1]. An electron beam is separated by a fine biprism wire and guided a few micrometers above a silicon waver where interference and naturally decoherence occurs. The separated electron states gain ’which-path’ information, when the electron wave suffers dissipation or it is weakly localized at the surface of the silicon waver. It can be clearly observed, that the interference contrast decreases with smaller beam distances towards the surface. We compare the results to an ’ab inito’ theoretical description of electronic interaction and decoherence above a semiconductor surface. Decoherence is perfectly suited for investigations of material properties, so it might be possible to distinguish surface effects from bulk influences by fine-tuning the distance of flight above the surface.

[1] P. Sonnentag and F. Hasselbach, PRL 98, 200402 (2007)