Advancing quantum process tomography through universal compilation

Abstract: Quantum process tomography (QPT) is crucial for characterizing operations in quantum gates and circuits, however, existing methods face scalability and noise sensitivity challenges. Here, we propose a QPT approach based on universal compilation, which systematically decomposes quantum processes into optimized Kraus operators and Choi matrices. This method utilizes efficient algorithms to improve accuracy while reducing resource requirements. We benchmark our approach through numerical simulations of random unitary gates, demonstrating highly accurate quantum process characterization. Additionally, we apply it to dephasing processes with time-homogeneous and time-inhomogeneous noise, achieving improved fidelity and robustness. Our work further enables broader applications in quantum error correction and device validation.