Error-Corrected Qubits via Erasure Conversion

Achieving fault tolerance through quantum error correction (QEC) is essential for implementing large-scale quantum algorithms with practical advantages. However, the associated overhead remains a significant challenge. This overhead can be mitigated by engineering physical qubits with reduced error rates and by tailoring residual errors to make them more easily correctable. Here, we demonstrate QEC codes and logical qubit operations using metastable-state qubits in ¹⁷¹Yb, which exhibit a biased noise model favoring erasure errors. The locations of these errors can be detected mid-circuit [1], enabling a more resource-efficient QEC approach [2]. Using a [[4,2,2]] code, we realize error-corrected logical qubits with an overhead of just two physical qubits per logical qubit. While this small code cannot correct general Pauli errors, it achieves error correction through mid-circuit erasure detection during decoding. Additionally, we demonstrate logical qubit teleportation between multiple logical blocks, using conditionally selected ancilla blocks informed by mid-circuit erasure checks. This approach provides a blueprint for leakage-robust error correction with neutral atom systems. We will also discuss progress in enhancing entangling gate fidelities and realizing locally addressed single-qubit gates.

[1] Ma, S., et al. "High-fidelity gates and mid-circuit erasure conversion in an atomic qubit." Nature 622.7982: 279-284 (2023)

[2] Wu, Y., et al. "Erasure conversion for fault-tolerant quantum computing in alkaline earth Rydberg atom arrays." Nature communications 13.1: 4657 (2022)