Quantum synchronization in dimer atomic lattices

Abstract

Synchronization phenomena have been recently reported in the quantum realm at atomic level due to collective dissipation. In this work [1] we propose a dimer lattice of trapped atoms realizing a dissipative spin model where quantum synchronization occurs instead in presence of local dissipation. Atoms synchronization is enabled by inhomogeneity of staggered local losses in the lattice and is favored by an increase of spins detuning. A comprehensive approach to quantum synchronization based on different measures considered in the literature allows to identify the main features of different synchronization regimes.

In panel (a) of the attached figure, we show a scheme of the atomic proposal to implement an effective 1D dissipative XX spin chain. The atomic system is described by a two-band Bose-Hubbard model in the Mott-Insulator regime. Lattice anharmonicity, strong on-site atom-atom repulsion, and perturbative contributions due to weak coupling lead to the desired effective spin model. Engineered dissipation is accomplished by optically addressing the internal (Λ) structure of the atomic states in the Lamb-Dicke regime. In panel (b) we show how spontaneous synchronization emerges when the decay rates become staggered (the order parameter for synchronization CT goes to one). Finally, in the inset, we show an example of synchronized trajectories for the coherences of a chain of four spins. We can appreciate how, in spite of the different intrinsic frequencies of the spins, they oscillate at the same frequency and with the relative phases locked.