Fault-tolerant protection of near-term trapped-ion topological qubits under realistic noise sources

TL;DR

This paper demonstrates that flag-qubit-based fault-tolerant techniques can enable beneficial quantum error correction in near-term trapped-ion quantum processors, offering a detailed noise model and simulation-based comparison with cat-based methods.

Contribution

It introduces optimized flag-qubit protocols tailored for trapped-ion systems and provides comprehensive microscopic noise modeling and simulation results.

Findings

Flag-qubit protocols outperform cat-based methods in simulations

Detailed noise characterization enhances fault-tolerance accuracy

Achieves the break-even point for beneficial quantum error correction

Abstract

The quest of demonstrating beneficial quantum error correction in near-term noisy quantum processors can benefit enormously from a low-resource optimization of fault-tolerant schemes, which are specially designed for a particular platform considering both state-of-the-art technological capabilities and main sources of noise. In this work, we show that flag-qubit-based fault-tolerant techniques for active error detection and correction, as well as for encoding of logical qubits, can be leveraged in current designs of trapped-ion quantum processors to achieve this break-even point of beneficial quantum error correction. Our improved description of the relevant sources of noise, together with detailed schedules for the implementation of these flag-based protocols, provide one of the most complete microscopic characterizations of a fault-tolerant quantum processor to date. By extensive numerical simulations, we provide a comparative study of flag- and cat-based approaches to quantum error correction, and show that the superior performance of the former can become a landmark in the success of near-term quantum computing with noisy trapped-ion devices.