Harnessing resonant dipolar interactions in a hybrid atom-molecule quantum system

Abstract

Hybrid quantum systems offer a route to combining the complementary strengths of distinct quantum platforms while mitigating their limitations. A particularly promising architecture combines neutral atoms and polar molecules: atoms provide fast, controllable interactions through excitation to Rydberg states, while molecules possess long-lived rotational states that are attractive for quantum memories and qudits. Although dipolar interactions between atoms and molecules have been observed in gas-phase and beam experiments, they have not previously been explored in a scalable optical tweezer platform that enables the controlled coherent interactions needed for quantum state transfer and entanglement. Here, we realise this goal, demonstrating coherent dipolar interactions between an individual Rydberg atom and an individual polar molecule. The separation of the particles is controlled using species-specific optical tweezers and their dipolar interactions are made strongly state-dependent by tuning two atom-molecule pair states into resonance. We exploit these interactions to demonstrate atom-mediated state readout of a molecular qubit, observe coherent spin exchange between the particles, and generate entanglement using a blockade-based controlled-NOT operation. Together, these results establish a coherent atom-molecule interface in which long-lived molecular quantum information can be rapidly mapped onto internal states of a Rydberg atom for readout or onward coherent transfer. This platform can be scaled to realise hybrid quantum processors utilising atom-mediated readout and entanglement of molecular qubits and mixed-species quantum simulators of dipolar systems.