High-fidelity gates with mid-circuit erasure conversion in a metastable neutral atom qubit

Neutral atom qubits have progressed rapidly in recent years. Exploring new atomic species, such as alkaline earth atoms 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 more favorable error models, such as erasure-dominated errors [1]. In this work, 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 [2]. Importantly, a significant 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. We will also discuss ongoing experiments to extend the two-qubit gate fidelity through detailed modeling of ¹⁷¹Yb Rydberg states, and the implementation of complex quantum circuits leveraging erasure conversion.