  Gate-set tomography (GST) characterizes the process matrix of quantum logic
gates, along with measurement and state preparation errors in quantum
processors. GST typically requires extensive data collection and significant
computational resources for model estimation. We propose a more efficient GST
approach for qudits, utilizing the qudit Hadamard and virtual Z gates to
construct fiducials while assuming virtual Z gates are error-free. Our method
reduces the computational costs of estimating characterization results, making
GST more practical at scale. We experimentally demonstrate the applicability of
this approach on a superconducting transmon qutrit.
