Exploring correlated hopping along a synthetic dimension in a strontium cavity QED system

Cavity quantum electrodynamics (cavity QED) is a promising platform for quantum science, enabling the engineering of long-range correlations between atoms, which has led to recent applications in quantum sensing, computing, and simulation. A recent theory proposal [1] discussed a possible new interaction for the cavity QED toolbox: correlated hopping of atoms within a manifold of hyperfine sublevels acting as a synthetic ladder of states. In an ensemble of 87-Sr atoms, which features a ladder of 10 sublevels in the F=9/2 ground state manifold, this proposed interaction induces atoms to coherently hop up or down several rungs of the ladder in pairs, extending previous demonstrations of pair creation in atom-cavity systems [2]. Here, we present progress towards engineering this physics. By applying detuned drives and utilizing cavity-mediated photon exchange interactions, we generate correlated hopping between sublevels while suppressing uncorrelated single-particle and collective Raman processes. We employ nondestructive, state-dependent cavity readout techniques to characterise correlations in all 10 sublevel populations. In addition, we truncate the ground state manifold to 2 adjacent sublevels, and observe mean-field dynamics induced by similar pair creation pathways.

[1] A. Chu, A. Piñeiro Orioli, D. Barberena, J. K. Thompson, and A. M. Rey, Phys. Rev. Res. 5, L022034 (2023).

[2] E. J. Davis, G. Bentsen, L. Homeier, T. Li, and M. H. Schleier-Smith, Phys. Rev. Lett. 122, 010405 (2019).