A dual-species Rydberg array

TL;DR

This paper demonstrates a dual-species Rydberg atom array with rubidium and cesium, enabling enhanced interspecies interactions, quantum state transfer, entanglement, and non-demolition measurements, advancing scalable quantum information processing.

Contribution

The work introduces a dual-species Rydberg array with tunable interspecies interactions, novel entanglement protocols, and midcircuit measurement capabilities, expanding quantum simulation and computation possibilities.

Findings

Achieved interspecies Rydberg blockade via electric tuning near Forster resonance.

Demonstrated quantum state transfer between Rb and Cs atoms.

Generated Bell states and performed quantum non-demolition measurements.

Abstract

Rydberg atom arrays have emerged as a leading platform for quantum information science. Reaching system sizes of hundreds of long-lived qubits, these arrays are used for highly coherent analog quantum simulation, as well as digital quantum computation. Advanced quantum protocols such as quantum error correction, however, require midcircuit qubit operations, including the replenishment, reset, and readout 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. Here, we realize a dual-species Rydberg array consisting of rubidium (Rb) and cesium (Cs) atoms, and explore new regimes of interactions and dynamics not accessible in single-species architectures. 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 implement quantum state transfer from one species to another. We then generate a Bell state between Rb and Cs hyperfine qubits via an interspecies controlled-phase gate. Finally, we combine interspecies entanglement with native midcircuit readout to achieve quantum non-demolition measurement of a Rb qubit using an auxiliary Cs qubit. The techniques demonstrated here pave the way toward scalable measurement-based protocols and real-time feedback control in large-scale quantum systems.