Interplay between coherent and dissipative dynamics of bosonic doublons in an optical lattice

TL;DR

This study investigates how dissipative processes, especially three-body losses, influence the dynamics of bosonic atom pairs in an optical lattice, revealing asymmetric decay behaviors and complex interplay between coherent and dissipative effects.

Contribution

It provides a detailed experimental and theoretical analysis of dissipative many-body dynamics in bosonic systems, highlighting the role of strong three-body loss and non-trivial lattice effects.

Findings

Rapid breakup of bound pairs at weak interactions

Asymmetric doublon decay rates for attractive and repulsive interactions

Dependence of decay rates on interaction strength and on-site loss

Abstract

We observe the dissipative dynamics of a dense, strongly interacting gas of bosonic atom pairs in an optical lattice, controlling the strength of the two-body interactions over a wide parameter regime. We study how three-body losses contribute to the lattice dynamics, addressing a number of open questions related to the effects of strong dissipation in a many-body system, including the relationship to the continuous quantum Zeno effect. We observe rapid break-up of bound pairs for weak interactions, and for stronger interactions we see doublon decay rates that are asymmetric when changing from attractive and repulsive interactions, and which strongly depend on the interactions and on-site loss rates. By comparing our experimental data with a theoretical analysis of few-body dynamics, we show that these features originate from a non-trivial combination of dissipative dynamics described by a lattice model beyond a standard Bose-Hubbard Hamiltonian, and the modification of three-atom dynamics on a single site, which is generated alongside strong three-body loss. Our results open new possibilities for investigating bosonic atoms with strong three-body loss features, and allow for the better understanding of the parameter regimes that are required to realize strong effective three-body interactions.