Characterizing mid-circuit measurements with a new form of gate set tomography part 2: Experiment*

Quantum computers rely on classical electronics for qubit control and readout. An important capability for the implementation of complex algorithms such as quantum error correction is the ability to operate the classical hardware in a feedback loop with the quantum processor. Mid-circuit measurements are the key operation in this type of control scheme, and their efficient and precise characterization will be critical to understanding the performance of algorithms on near-term quantum devices. To that end, we demonstrate the use of an extension to gate set tomography (GST), a highly accurate protocol for diagnosing quantum processes, to characterize intermediate measurements on a superconducting transmon qubit.