Rigorous measurement error correction
Michael R Geller · Quantum Science and Technology · 2020
Abstract We review an experimental technique used to correct state preparation and measurement errors on gate-based quantum computers, and discuss its rigorous justification. Within a specific biased quantum measurement model, we prove that nonideal measurement of an arbitrary n -qubit state is equivalent to ideal projective measurement followed by a classical Markov process Γ acting on the output probability distribution. Measurement errors can be removed, with rigorous justification, if Γ can be learned and inverted. We show how to obtain Γ from gate set tomography (Blume-Kohout et al arXiv:1310.4492) and apply the rigorous correction technique to single IBM Q superconducting qubits.