January 22, 2024 | Shraddha Anand, Conor E. Bradley, Ryan White, Vikram Ramesh, Kevin Singh, and Hannes Bernien
This paper presents a dual-species Rydberg array consisting of rubidium (Rb) and cesium (Cs) atoms, demonstrating new interaction regimes and dynamics not accessible in single-species systems. The array enables interspecies Rydberg blockade and quantum state transfer between species, as well as the generation of Bell states via an interspecies controlled-phase gate. The study also shows how to perform quantum non-demolition (QND) measurement of a Rb qubit using an auxiliary Cs qubit, combining interspecies entanglement with midcircuit readout. The techniques demonstrated pave the way for scalable measurement-based protocols and real-time feedback control in large-scale quantum systems.
The dual-species Rydberg array is implemented using optical tweezers and allows for independent control of the two species, enabling access to unexplored dynamical regimes in globally driven Rydberg arrays. The unique addressing frequencies for each species result in independent control, crosstalk-free measurement, and straightforward methods for generating Rydberg-based entanglement between them. The intrinsic addressability of qubits allows for universal control schemes, efficient state preparation, and the study of novel Hamiltonians, while maintaining a minimal control architecture of two separate global drives.
The study demonstrates the first observation of an interspecies Förster resonance between individually trapped atoms, which gives rise to long-range interactions, anisotropy, and tunable inter:intra-species interaction. The results show that the interspecies Förster interaction results in a slower fall-off than the vdW interactions, and the interaction strengths are measured and compared with theoretical predictions. The study also demonstrates interspecies Rydberg blockade and dynamics, showing that the doubly-excited state shifts out of resonance, leading to strong blockade dynamics.
The paper also presents the first interspecies logic operations in an atom array, demonstrating the generation of a maximally entangled Bell state and the implementation of quantum non-demolition detection of the Rb state using the Cs qubit as an auxiliary. The results show that the measured SPAM-corrected fidelity is in good agreement with the error model, and the study highlights the potential of dual-species Rydberg arrays for quantum error correction and the generation of long-range entangled states in large systems. The study also discusses the potential for future improvements in operation fidelities and the addition of fast, Raman-based single-qubit operations, local-addressing techniques, and non-destructive readout to enable increasingly complex protocols.This paper presents a dual-species Rydberg array consisting of rubidium (Rb) and cesium (Cs) atoms, demonstrating new interaction regimes and dynamics not accessible in single-species systems. The array enables interspecies Rydberg blockade and quantum state transfer between species, as well as the generation of Bell states via an interspecies controlled-phase gate. The study also shows how to perform quantum non-demolition (QND) measurement of a Rb qubit using an auxiliary Cs qubit, combining interspecies entanglement with midcircuit readout. The techniques demonstrated pave the way for scalable measurement-based protocols and real-time feedback control in large-scale quantum systems.
The dual-species Rydberg array is implemented using optical tweezers and allows for independent control of the two species, enabling access to unexplored dynamical regimes in globally driven Rydberg arrays. The unique addressing frequencies for each species result in independent control, crosstalk-free measurement, and straightforward methods for generating Rydberg-based entanglement between them. The intrinsic addressability of qubits allows for universal control schemes, efficient state preparation, and the study of novel Hamiltonians, while maintaining a minimal control architecture of two separate global drives.
The study demonstrates the first observation of an interspecies Förster resonance between individually trapped atoms, which gives rise to long-range interactions, anisotropy, and tunable inter:intra-species interaction. The results show that the interspecies Förster interaction results in a slower fall-off than the vdW interactions, and the interaction strengths are measured and compared with theoretical predictions. The study also demonstrates interspecies Rydberg blockade and dynamics, showing that the doubly-excited state shifts out of resonance, leading to strong blockade dynamics.
The paper also presents the first interspecies logic operations in an atom array, demonstrating the generation of a maximally entangled Bell state and the implementation of quantum non-demolition detection of the Rb state using the Cs qubit as an auxiliary. The results show that the measured SPAM-corrected fidelity is in good agreement with the error model, and the study highlights the potential of dual-species Rydberg arrays for quantum error correction and the generation of long-range entangled states in large systems. The study also discusses the potential for future improvements in operation fidelities and the addition of fast, Raman-based single-qubit operations, local-addressing techniques, and non-destructive readout to enable increasingly complex protocols.