A hybrid atom tweezer array of nuclear spin and optical clock qubits

TL;DR

This paper demonstrates a hybrid ytterbium atom array combining nuclear spin and optical clock qubits, enabling non-destructive readout and minimal crosstalk, advancing quantum error correction capabilities.

Contribution

It introduces a dual-isotope Yb atom array with integrated data and ancilla qubits, showcasing high-fidelity, low-crosstalk qubit control suitable for fault-tolerant quantum computing.

Findings

Achieved 99.1% coherence retention over 20 ms exposure.

Demonstrated non-destructive qubit readout with 0.9992 fidelity.

Observed negligible impact on nuclear spin coherence from imaging light.

Abstract

While data qubits with a long coherence time are essential for the storage of quantum information, ancilla qubits are pivotal in quantum error correction (QEC) for fault-tolerant quantum computing. The recent development of optical tweezer arrays, such as the preparation of large-scale qubit arrays and high-fidelity gate operations, offers the potential for realizing QEC protocols, and one of the important next challenges is to control and detect ancilla qubits while minimizing atom loss and crosstalk. Here, we present the realization of a hybrid system consisting of a dual-isotope ytterbium (Yb) atom array, in which we can utilize a nuclear spin qubit of fermionic ${}^{171}\mathrm{Yb}$ as a data qubit and an optical clock qubit of bosonic ${}^{174}\mathrm{Yb}$ as an ancilla qubit with a capacity of non-destructive qubit readout. We evaluate the crosstalk between qubits regarding the impact on the coherence of the nuclear spin qubits from the imaging light for ${}^{174}\mathrm{Yb}$. The Hahn-echo sequence with a 399 nm probe and 556 nm cooling beams for ${}^{174}\mathrm{Yb}$, we observe 99.1(1.8) % coherence retained under 20 ms exposure, yielding an imaging fidelity of 0.9992 and a survival probability of 0.988. The Ramsey sequence with a 556 nm probe beam shows negligible influence on the coherence, suggesting the potential future improvement of low cross-talk measurements. This result highlights the potential of the hybrid-Yb atom array for ancilla-qubit-based QEC protocols.