Hannover 2013 – scientific programme
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Q: Fachverband Quantenoptik und Photonik
Q 26: Ultra-cold atoms, ions and BEC III (with A)
Q 26.3: Talk
Tuesday, March 19, 2013, 11:30–11:45, B 302
Interference effects in Fock space in Bose-Hubbard systems — •Thomas Engl1, Juan Diego Urbina1, Arturo Argüelles Parra2, Julien Dujardin2, Peter Schlagheck2, and Klaus Richter1 — 1Universität Regensburg — 2Universite de Liege
Semiclassical techniques have so far been applied mainly to single particle systems. For these systems they provide a powerful toolbox to study interference effects and allow analytical calculations even in the presence of classical chaos.
On the other hand there have been attempts to apply the semiclassical approximation to the Feynman path integral for bosonic quantum fields in coherent state representation. The resulting coherent state path integral however leads to complex actions which does not give clear insight in interference effects.
We have succeeded in finding a representation in which the semiclassical approximation leads to a van-Vleck propagator with real action and therefore shows interference in Fock space explicitly. We use this propagator to predict various interference effects for Bose-Hubbard systems in three different regimes of the ratio of interaction and hopping strength, and we show that the probability of return is enhanced due to interference.