Quantum Circuit Repair by Gate Prioritisation

TL;DR

QRep is an automated quantum circuit repair method that iteratively identifies and prioritizes suspicious gates to efficiently fix faults, demonstrating high success rates and scalability.

Contribution

The paper introduces QRep, a novel fault repair approach for quantum circuits that improves efficiency through gate prioritization and fault localization.

Findings

QRep repaired 70% of tested faulty circuits completely.

The actual faulty gate was ranked within the top 44% of suspicious gates.

QRep scales to circuits with up to 13 qubits.

Abstract

Repairing faulty quantum circuits is challenging and requires automated solutions. We present QRep, an automated repair approach that iteratively identifies and repairs faults in a circuit. QRep uniformly applies patches across the circuit and assigns each gate a suspiciousness score, reflecting its likelihood of being faulty. It then narrows the search space by prioritising the most suspicious gates in subsequent iterations, increasing the repair efficiency. We evaluated QRep on 40 (real and synthetic) faulty circuits. QRep completely repaired 70% of them, and for the remaining circuits, the actual faulty gate was ranked within the top 44% most suspicious gates, demonstrating the effectiveness of QRep in fault localisation. Compared with two baseline approaches, QRep scales to larger and more complex circuits, up to 13 qubits.