Atoms Interlinked by Light: Programmable Nonlocal Interactions for Quantum Simulation

The connectivity of interactions in a quantum simulator plays a crucial role in dictating which problems can efficiently be mapped onto the hardware. While local interactions are well suited to simulating a wide range of problems in condensed-matter physics, adding nonlocal connectivity opens the door to new applications, from simulating models of quantum gravity to manipulating topologically encoded quantum information. I will report on experiments in which we achieve programmable nonlocal connectivity within an array of atom clouds trapped in an optical resonator, letting photons mediate interactions between distant atoms. We have harnessed this toolbox to simulate a toy model of holographic duality and to interferometrically probe topological edge states. To illustrate the capacity for accessing demonstrably entangled states, we have further demonstrated a versatile protocol for preparing graph states enabling a quantum enhancement in multiparameter sensing.