Trojan quasiparticles

Abstract

We argue that a time-periodically driven bosonic Josephson junction supports stable, quasi-particle-like collective response modes which are $N$-particle analogs of the nonspreading Trojan wave packets known from microwave-driven Rydberg atoms. Similar to their single-particle counterparts, these collective modes, dubbed "flotons", are well described by a Floquet-Mathieu approximation, and possess a well-defined discrete set of excitations. In contrast to other, "chaotic" modes of response, the nonheating Trojan modes conform to a mean-field description, and thus may be of particular interest for the more general question under which conditions the reduction of quantum $N$-particle dynamics to a strongly simplified mean-field evolution is feasible. Our reasoning is supported by phase-space portraits which reveal the degree of correspondence beween the $N$-particle dynamics und the mean-field picture in an intuitive manner.

15 pages, 10 figures

References in corpus (3)

• Comparing and contrasting nuclei and cold atomic gases
• Differences between mean-field dynamics and N-particle quantum dynamics as a signature of entanglement
• Semiclassical quantization of an N-particle Bose-Hubbard model

Cited by in corpus (2)

• Fluctuations of the order parameter of a mesoscopic Floquet condensate
• Quasiparticle tunneling in a periodically driven bosonic Josephson junction