On the Efficacy of Surface Codes in Compensating for Radiation Events in Superconducting Devices

TL;DR

This paper evaluates how surface codes can improve the resilience of superconducting quantum computers against radiation-induced faults, demonstrating up to a 10% increase in fault correction probability through proper code tuning.

Contribution

It provides empirical data on the effectiveness of surface codes against radiation faults and offers guidelines for designing more robust quantum error correction codes.

Findings

Surface code tuning can increase fault correction probability by up to 10%.

Radiation-induced logical error rates depend on code distance and physical qubit configuration.

Proper code selection enhances quantum computer reliability without additional overhead.

Abstract

Reliability is fundamental for developing large-scale quantum computers. Since the benefit of technological advancements to the qubit's stability is saturating, algorithmic solutions, such as quantum error correction (QEC) codes, are needed to bridge the gap to reliable computation. Unfortunately, the deployment of the first quantum computers has identified faults induced by natural radiation as an additional threat to qubits reliability. The high sensitivity of qubits to radiation hinders the large-scale adoption of quantum computers, since the persistence and area-of-effect of the fault can potentially undermine the efficacy of the most advanced QEC. In this paper, we investigate the resilience of various implementations of state-of-the-art QEC codes to radiation-induced faults. We report data from over 400 million fault injections and correlate hardware faults with the logical error observed after decoding the code output, extrapolating physical-to-logical error rates. We compare the code's radiation-induced logical error rate over the code distance, the number and role in the QEC of physical qubits, the underlying quantum computer topology, and particle energy spread in the chip. We show that, by simply selecting and tuning properly the surface code, thus without introducing any overhead, the probability of correcting a radiation-induced fault is increased by up to 10\%. Finally, we provide indications and guidelines for the design of future QEC codes to further increase their effectiveness against radiation-induced events.