IQIM Postdoctoral and Graduate Student Seminar

Abstract: Rydberg atom arrays are a leading platform for quantum information due to their inherent scalability and flexible connectivity. Advanced protocols like measurement-based state preparation and quantum error correction, however, require efficient crosstalk-free midcircuit operations for the readout, reset, and replenishment of a subset of qubits. These capabilities are natively present in dual-species architectures where two atomic species are controlled independently and entangled via interspecies Rydberg interactions. In this talk, we describe a platform composed of rubidium (Rb) and cesium (Cs) atoms, and explore new dynamics inaccessible in single-species arrays. First, we demonstrate enhanced interspecies interactions by exciting atoms to Rydberg states in the Förster regime, and implement the first interspecies CNOT gate. We then combine this with midcircuit readout to achieve quantum non-demolition measurement of a Rb-qubit using an auxiliary Cs-qubit, circumventing physical qubit transport. Using a spectator qubit protocol, we also perform in-sequence correction of correlated phase errors. Finally, leveraging the two qubit modalities and using only global addressing, we present the first experimental demonstration of quantum cellular automata. By programming the initial states and subsequent pulses, we simulate several automata schemes, and use Rb-mediated interactions to generate a 17-qubit Cs cluster state. These techniques pave the way toward scalable measurement-based protocols and real-time feedback control in large-scale quantum systems.

Following the talk, lunch will be provided on the lawn outside East Bridge.