  Real-time scattering calculations on a Noisy Intermediate Scale Quantum
(NISQ) quantum computer are disrupted by errors that accumulate throughout the
circuits. To improve the accuracy of such physics simulations, one can
supplement the application circuits with a recent error mitigation strategy
known as Noisy Output eXtrapolation (NOX). We tested these error mitigation
protocols on a Transverse Field Ising model and improved upon previous
calculations of the phase shift. Our proof-of-concept 4-qubit application
circuits were run on several IBM quantum computing hardware architectures.
Metrics were introduced that show between 21\% and 74\% error reduction for
circuit depths ranging from 14 to 37 hard cycles, confirming that the NOX
technique applies to circuits with a broad range of failure rates. This
observation on different cloud-accessible devices further confirms that NOX
provides performance improvements even in the advent where circuits are
executed in substantially time-separated batches. Finally, we provide a
heuristic method to obtain systematic error bars on the mitigated results,
compare them with empirical errors and discuss their effects on phase shift
estimates.
