- Award ID(s):
- 1753386
- PAR ID:
- 10159809
- Publisher / Repository:
- Nature Physics
- Date Published:
- Journal Name:
- Nature physics
- ISSN:
- 1745-2473
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Minimizing and understanding errors is critical for quantum science, both in noisy intermediate scale quantum (NISQ) devices1 and for the quest towards fault-tolerant quantum computation2,3. Rydberg arrays have emerged as a prominent platform in this context4 with impressive system sizes5,6 and proposals suggesting how error-correction thresholds could be significantly improved by detecting leakage errors with single-atom resolution7,8, a form of erasure error conversion9,10,11,12. However, two-qubit entanglement fidelities in Rydberg atom arrays13,14 have lagged behind competitors15,16 and this type of erasure conversion is yet to be realized for matter-based qubits in general. Here we demonstrate both erasure conversion and high-fidelity Bell state generation using a Rydberg quantum simulator5,6,17,18. When excising data with erasure errors observed via fast imaging of alkaline-earth atoms19,20,21,22, we achieve a Bell state fidelity of ≥0.9971−13+10, which improves to ≥0.9985−12+7 when correcting for remaining state-preparation errors. We further apply erasure conversion in a quantum simulation experiment for quasi-adiabatic preparation of long-range order across a quantum phase transition, and reveal the otherwise hidden impact of these errors on the simulation outcome. Our work demonstrates the capability for Rydberg-based entanglement to reach fidelities in the 0.999 regime, with higher fidelities a question of technical improvements, and shows how erasure conversion can be utilized in NISQ devices. These techniques could be translated directly to quantum-error-correction codes with the addition of long-lived qubits7,22,23,24.more » « less
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Abstract Minimizing and understanding errors is critical for quantum science, both in noisy intermediate scale quantum (NISQ) devices1and for the quest towards fault-tolerant quantum computation2,3. Rydberg arrays have emerged as a prominent platform in this context4with impressive system sizes5,6and proposals suggesting how error-correction thresholds could be significantly improved by detecting leakage errors with single-atom resolution7,8, a form of erasure error conversion9–12. However, two-qubit entanglement fidelities in Rydberg atom arrays13,14have lagged behind competitors15,16and this type of erasure conversion is yet to be realized for matter-based qubits in general. Here we demonstrate both erasure conversion and high-fidelity Bell state generation using a Rydberg quantum simulator5,6,17,18. When excising data with erasure errors observed via fast imaging of alkaline-earth atoms19–22, we achieve a Bell state fidelity of
, which improves to$$\ge 0.997{1}_{-13}^{+10}$$ when correcting for remaining state-preparation errors. We further apply erasure conversion in a quantum simulation experiment for quasi-adiabatic preparation of long-range order across a quantum phase transition, and reveal the otherwise hidden impact of these errors on the simulation outcome. Our work demonstrates the capability for Rydberg-based entanglement to reach fidelities in the 0.999 regime, with higher fidelities a question of technical improvements, and shows how erasure conversion can be utilized in NISQ devices. These techniques could be translated directly to quantum-error-correction codes with the addition of long-lived qubits7,22–24.$$\ge 0.998{5}_{-12}^{+7}$$ -
Theory for one and two atom interactions is developed for the case when the atoms have a Rydberg electron attached to a hyper- fine split core state, a situation relevant for some rare earth and some alkaline earth atoms proposed for experiments on Rydberg-Rydberg in- teractions. For the rare earth atoms, the core electrons can have a very substantial total angular momentum, J, and a non-zero nuclear spin, I. For alkaline earth atoms there is a single, s, core electron whose spin can couple to a non-zero nuclear spin for odd isotopes. The hyperfine splitting of the core state can lead to substantial mixing between the Rydberg series attached to different thresholds. Compared to the un- perturbed Rydberg series of the alkali atoms, series perturbations and near degeneracies from the different parity states could lead to quali- tatively different behavior for single atom Rydberg properties (polariz- ability, Zeeman mixing and splitting, etc) as well as Rydberg-Rydberg interactions (C5 and C6 matrices).more » « less
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Abstract Atomic systems, ranging from trapped ions to ultracold and Rydberg atoms, offer unprecedented control over both internal and external degrees of freedom at the single‐particle level. They are considered among the foremost candidates for realizing quantum simulation and computation platforms that can outperform classical computers at specific tasks. In this work, a realistic experimental toolbox for quantum information processing with neutral alkaline‐earth‐like atoms in optical tweezer arrays is described. In particular, a comprehensive and scalable architecture based on a programmable array of alkaline‐earth‐like atoms is proposed, exploiting their electronic clock states as a precise and robust auxiliary degree of freedom, and thus allowing for efficient all‐optical one‐ and two‐qubit operations between nuclear spin qubits. The proposed platform promises excellent performance thanks to high‐fidelity register initialization, rapid spin‐exchange gates, and error detection in read‐out. As a benchmark and application example, the expected fidelity of an increasing number of subsequent SWAP gates for optimal parameters is computed, which can be used to distribute entanglement between remote atoms within the array.
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The development of scalable, high-fidelity qubits is a key challenge in quantum information science. Neutral atom qubits have progressed rapidly in recent years, demonstrating programmable processors1,2 and quantum simulators with scaling to hundreds of atoms3,4. Exploring new atomic species, such as alkaline earth atoms5,6,7, or combining multiple species8 can provide new paths to improving coherence, control and scalability. For example, for eventual application in quantum error correction, it is advantageous to realize qubits with structured error models, such as biased Pauli errors9 or conversion of errors into detectable erasures10. Here we demonstrate a new neutral atom qubit using the nuclear spin of a long-lived metastable state in 171Yb. The long coherence time and fast excitation to the Rydberg state allow one- and two-qubit gates with fidelities of 0.9990(1) and 0.980(1), respectively. Importantly, a large fraction of all gate errors result in decays out of the qubit subspace to the ground state. By performing fast, mid-circuit detection of these errors, we convert them into erasure errors; during detection, the induced error probability on qubits remaining in the computational space is less than 10−5. This work establishes metastable 171Yb as a promising platform for realizing fault-tolerant quantum computing.more » « less