Quantum signatures of an oscillatory instability in the Bose-Hubbard trimer
2012 (English)Conference paper, Abstract (Other academic)
We study the Bose-Hubbard model for three sites in a symmetric, triangular configuration, and search for quantumsignatures of the classical regime of oscillatory instabilities, known to appear through Hamiltonian Hopfbifurcations for the single-depleted well family of stationary states in the Discrete Nonlinear Schrödinger equation.In the regimes of classical stability, single quantum eigenstates with properties analogous to the classicalstationary states can be identified already for rather small particle numbers. On the other hand, in the instabilityregime the interaction with other eigenstates through avoided crossings leads to strong mixing, andno single eigenstate with classical-like properties can be seen. We compare the quantum dynamics resultingfrom initial conditions taken as perturbed quantum eigenstates, and SU(3) coherent states, respectively, in aquantum-semiclassical transitional regime of 10-100 particles. While the perturbed quantum eigenstates donot show a classical-like behaviour in the instability regime, a coherent state behaves analogously to a perturbedclassical stationary state, and exhibits initially resonant oscillations with oscillation frequencies welldescribed by classical internal-mode oscillations.
Place, publisher, year, edition, pages
2012. 18- p.
Other Physics Topics
IdentifiersURN: urn:nbn:se:liu:diva-88419OAI: oai:DiVA.org:liu-88419DiVA: diva2:603419
2nd Conference on Localized Excitations in Nonlinear Complex Systems (LENCOS'12), Sevilla (Spain), July 9-12, 2012
FunderSwedish Research Council, 621-2009-3554