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arXiv · 1604.03777

Bosonic Josephson effect in the Fano-Anderson model

G. Engelhardt·G. Schaller·T. Brandes
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Abstract

We investigate the coherent dynamics of a non-interacting Bose-Einstein condensate in a system consisting of two bosonic reservoirs coupled via a spatially localized mode. We describe this system by a two-terminal Fano-Anderson model and investigate analytically the time evolution of observables such as the bosonic Josephson current. In doing so, we find that the Josephson current sensitively depends on the on-site energy of the localized mode. This facilitates to use this setup as a transistor for a Bose-Einstein condensate. We identify two regimes. In one regime, the system exhibits well-behaved long-time dynamics with a slowly oscillating and undamped Josephson current. In a second regime, the Josephson current is a superposition of an extremely weakly damped slow oscillation and an undamped fast oscillation. Our results are confirmed by finite-size simulations.

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G. Engelhardt, G. Schaller, T. Brandes. 2016-04-13. Bosonic Josephson effect in the Fano-Anderson model. https://doi.org/10.1103/physreva.94.013608

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