Characterization of State-dependent Noise in NISQ Processors

Characterization of the quantum operations in current NISQ devices reveal noise spectra that are highly dependent on the underlying quantum state. These results indicate that a state-dependent noise model is needed to accurately control the behavior of quantum computing programs on today’s noisy hardware. We develop a method for characterizing state-dependent errors based on classical truth tables for the gate operations, and we use these results to compute the amplitudes of the corresponding channel operators. Using this method, we characterize a 20-qubit fixed-frequency superconducting transmon processor to develop a noise model for this device. We then use this noise model to estimate the fidelity of quantum circuits executed on the hardware and compare these results with tomographic fidelities.