Colloquium- Kevin Singh (University of Chicago)- A dual-species Rydberg array

Abstract: Rydberg atom arrays are a leading platform for quantum information science. Such arrays comprise hundreds of long-lived qubits that are used for highly coherent analog quantum simulation and digital quantum computation. Advanced quantum protocols such as quantum error correction, however, require midcircuit qubit operations, including readout, reset, and replenishment of a subset of qubits. A compelling strategy to achieve these capabilities is a dual-species architecture in which a second atomic species can be controlled without crosstalk and entangled with the first via Rydberg interactions. In this talk, I will present our realization of a dual-species Rydberg array consisting of rubidium (Rb) and cesium (Cs) atoms. I will discuss the richness of interaction regimes that can be accessed in the system and how we achieve enhanced interspecies interactions by electrically tuning the Rydberg states close to a Forster resonance. In this regime, we demonstrate interspecies Rydberg blockade and use this blockade to generate Bell states between Rb and Cs hyperfine qubits. I will discuss how we combine this interspecies entanglement with native midcircuit readout to achieve quantum non-demolition measurement of a Rb qubit using an auxiliary Cs qubit. Finally, I will discuss how these techniques enable scalable measurement-based protocols and real-time feedback control in large-scale quantum systems.