Wave-packet dynamics in energy space of a chaotic trimeric Bose-Hubbard system

Abstract

We study the energy redistribution of interacting bosons in a ring-shaped quantum trimer as the coupling strength between neighboring sites of the corresponding Bose-Hubbard Hamiltonian undergoes a sudden change $\ensuremath{\delta}k$. Our analysis is based on a threefold approach combining linear response theory calculations as well as semiclassical and random matrix theory considerations. The $\ensuremath{\delta}k$ borders of applicability of each of these methods are identified by direct comparison with the exact quantum-mechanical results. We find that while the variance of the evolving quantum distribution shows a remarkable quantum-classical correspondence (QCC) for all $\ensuremath{\delta}k$ values, other moments exhibit this QCC only in the nonperturbative $\ensuremath{\delta}k$ regime.