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

TL;DR

This paper introduces a new neutral atom qubit using metastable ${}^{171}$Yb, achieving high-fidelity gates and converting certain errors into detectable erasures, advancing the path toward fault-tolerant quantum computing.

Contribution

Demonstrates a novel ${}^{171}$Yb qubit with high-fidelity gates and mid-circuit erasure conversion, enhancing error detection for scalable quantum computing.

Findings

Gate fidelities of 0.9990(1) for single-qubit and 0.980(1) for two-qubit operations.

Significant errors are converted into erasures with less than 10^{-5} error probability during detection.

Metastable ${}^{171}$Yb is a promising platform for fault-tolerant quantum computing.

Abstract

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 processors and quantum simulators with scaling to hundreds of atoms. Exploring new atomic species, such as alkaline earth atoms, or combining multiple species 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 errors or conversion of errors into detectable erasures. In this work, we demonstrate a new neutral atom qubit, using the nuclear spin of a long-lived metastable state in ${}^{171}$Yb. 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 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 $10^{-5}$. This work establishes metastable ${}^{171}$Yb as a promising platform for realizing fault-tolerant quantum computing.