Abstract
We report on the realization of a fast, scalable, and high-fidelity qubit architecture, based on atoms in an optical tweezer array. We demonstrate several attractive properties of this atom for its use as a building block of a quantum information processing platform. Its nuclear spin of serves as a long-lived and coherent two-level system, while its rich, alkaline-earth-like electronic structure allows for low-entropy preparation, fast qubit control, and high-fidelity readout. We present a near-deterministic loading protocol, which allows us to fill a tweezer array with 92.73(8)% efficiency and a single tweezer with 96.0(1.4)% efficiency. In the future, this loading protocol will enable efficient and uniform loading of target arrays with high probability, an essential step in quantum simulation and information applications. Employing a robust optical approach, we perform submicrosecond qubit rotations and characterize their fidelity through randomized benchmarking, yielding error per Clifford gate. For quantum memory applications, we measure the coherence of our qubits with and , many orders of magnitude longer than our qubit rotation pulses. We measure spin depolarization times on the order of tens of seconds and find that this can be increased to the 100 s scale through the application of a several-gauss magnetic field. Finally, we use 3D Raman-sideband cooling to bring the atoms near their motional ground state, which will be central to future implementations of two-qubit gates that benefit from low motional entropy.
6 More- Received 13 December 2021
- Accepted 8 April 2022
DOI:https://doi.org/10.1103/PhysRevX.12.021027
Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI.
Published by the American Physical Society
Physics Subject Headings (PhySH)
Erratum
Erratum: Ytterbium Nuclear-Spin Qubits in an Optical Tweezer Array [Phys. Rev. X 12, 021027 (2022)]
Alec Jenkins, Joanna W. Lis, Aruku Senoo, William F. McGrew, and Adam M. Kaufman
Phys. Rev. X 13, 029902 (2023)
synopsis
A New Option for Neutral-Atom Quantum Computing
Published 3 May 2022
Two independent teams show that neutral ytterbium-171 atoms can be trapped and used for quantum information processing, bringing quantum computers based on this platform a step closer to reality.
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Popular Summary
Neutral atoms trapped in tightly focused beams of light (optical tweezers) are a powerful platform for quantum science. Using real-time control of the light field forming the tweezers, the platform allows for programmable control of the atoms themselves, which can act as high-fidelity qubits. Expanding tweezer trapping to more complex atoms could harness the complexity of these atoms for more sophisticated computing challenges. To that end, we for the first time trap ytterbium-171, a promising building block for a quantum information processing architecture, and demonstrate some of its appealing features.
The nuclear spin of ytterbium-171 acts as an intrinsic qubit that is insensitive to its environment, while its two active electrons give rise to optical transitions that allow for preparation of ultracold, almost fully filled arrays of atoms and fast, accurate manipulation of the qubits. We load individual atoms into each trap with record-breaking efficiencies, near-deterministically filling an array of 100 tweezers. Further, we demonstrate single-qubit control at timescales faster than , with accuracies of one error per 200 operations, and show that our qubits remain in their quantum state for seconds. Finally, we “freeze” the atoms in the traps, cooling them to near their motional ground state.
Combining these capabilities with clock states and entanglement generation in the future will allow for a vast range of quantum information processing and quantum-enhanced metrology applications.