Automated characterization and gate optimization of superconducting QPUs with fixed couplers

Precise control of single- and two-qubit gates is essential for realizing high-fidelity superposition and entanglement, forming the foundation of quantum algorithms for Quantum Error Correction [1], teleportation [2], and Quantum Amplitude Estimation (QAE), which promises advantages in chemistry, finance, and machine learning [3]. In superconducting platforms, calibration complexity and parameter drift remain major challenges in achieving reproducible gate performance.

We report ongoing experiments at the University of Napoli “Federico II” on a superconducting transmon-based Quantum Processing Unit (QPU) with fixed couplers, Contralto-D from QuantWare, specifically designed to run proof-of-concepts quantum algorithms at the Italian Superconducting Quantum Computing Center Partenope, e.g. surface codes towards fault-tolerant computing in the Noisy and Intermediate Scale Quantum (NISQ) era. Using an automated experimental platform Quantum EDGE developed by QuantrolOx, we carry out comprehensive characterization of qubit performance and systematic tuning of one- and two-qubit gates. The approach enables efficient and repeatable measurement cycles, reducing manual intervention while improving stability and reproducibility. We discuss results on gate performance and implications for near-term scalable mid-scale algorithms, such as advanced investigations of quantum states computational resources [6] and QAE for credit risk analysis [7].