Erasure conversion for fault-tolerant quantum computing in alkaline earth Rydberg atom arrays

Area of Science:

• Quantum Computing
• Atomic Physics
• Quantum Error Correction

Background:

• Scalable quantum computing requires error-corrected logical qubits, which are limited by current hardware's qubit count and physical error rates.
• Tailored error-correcting codes are emerging to mitigate these hardware constraints by addressing specific physical noise models.

Purpose of the Study:

• To propose a novel qubit encoding and gate protocol for ytterbium-171 (¹⁷¹Yb) neutral atom qubits.
• To convert dominant physical errors into erasures (errors in known locations) for enhanced quantum error correction.

Main Methods:

• Encoding qubits in a metastable electronic level of ¹⁷¹Yb neutral atoms.
• Utilizing gate operations that predominantly cause transitions to disjoint subspaces.
• Continuous monitoring of subspace populations via fluorescence to detect errors.
• Circuit-level simulations of the surface code to quantify the benefits.

Main Results:

• An estimated 98% of physical errors are converted into erasures.
• A significant increase in the surface code error threshold from 0.937% to 4.15%.
• Observed a larger code distance near the threshold, enabling faster logical error rate reduction.

Conclusions:

• The proposed erasure conversion protocol substantially enhances quantum error correction efficiency for ¹⁷¹Yb neutral atom qubits.
• This approach offers a promising pathway for near-term implementations of scalable quantum computing.
• Erasure conversion is a broadly applicable technique that can benefit various error-correcting codes and qubit platforms.