Quantum Error Mitigation Relying on Permutation Filtering

Quantum error mitigation (QEM) is a class of promising techniques capable reducing the computational variational quantum algorithms tailored for current noisy intermediate-scale computers. The recently proposed permutation-based methods are practically attractive, since they do not rely on any a priori information concerning channels. In this treatise, we propose general framework termed as permutation filters, which includes existing special cases. particular, show that filter design algorithm always converge to global optimum, and optimal filters can provide substantial improvements over in presence narrowband noise, corresponding large-depth, high-error-rate circuits.