Positive and negative quenches induced excitation dynamics for ultracold bosons in one-dimensional lattices

The correlated non-equilibrium dynamics of few-boson systems in one-dimensional finite lattices is investigated. Focusing on the low-lying modes of the finite lattice we observe the emergence of density-wave tunneling, breathing and cradle-like processes. In particular, the tunneling induced by the quench leads to a global density-wave oscillation. The resulting breathing and cradle modes are inherent to the local intrawell dynamics and related to excited-band states. Positive interaction quenches couple the density-wave and the cradle modes allowing for resonance phenomena [1]. Moreover, the cradle mode is associated with the initial delocalization and following a negative interaction quench can be excited for setups with filling larger than unity. For subunit fillings it can be accessed with the aid of a negative quench of the lattice depth [2]. Finally, our results shed light to possible controlling schemes for the cradle and the breathing modes. The evolution of the system is obtained numerically using the ab-initio multi-layer multi-configuration time-dependent Hartree method for bosons.\\[4pt] [1] S. I. Mistakidis, L. Cao, and P. Schmelcher, J. Phys. B: At. Mol. Opt. Phys. 47 225303 (2014). \\[0pt] [2] S. I. Mistakidis, L. Cao, and P. Schmelcher, arXiv preprint arXiv:1412.1375 (2014).