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arXiv · 1410.8008

Fluctuations of the order parameter of a mesoscopic Floquet condensate

Bettina Gertjerenken·Martin Holthaus
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Abstract

We suggest that nonequilibrium Bose-Einstein condensates may occur in time-periodically driven interacting Bose gases. Employing the model of a periodically forced bosonic Josephson junction, we demonstrate that resonance-induced ground state-like many-particle Floquet states possess an almost perfect degree of coherence, as corresponding to a mesoscopically occupied, explicitly time-dependent single-particle orbital. In marked contrast to the customary time-independent Bose-Einstein condensates, the order parameter of such systems is destroyed by violent fluctuations when the particle number becomes too large, signaling the non-existence of a proper mean field limit.

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Bettina Gertjerenken, Martin Holthaus. 2014-10-29. Fluctuations of the order parameter of a mesoscopic Floquet condensate. https://doi.org/10.1103/physreva.90.053614

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