This paper presents a novel index in order to characterize error propagation in quantum circuits by separating the resultant mixed error state in two components: an isotropic component, that quantifies the lack of information, and a dis-alignment component, that represents the shift between the current state and the original pure quantum state. The Isotropic Triangle, a graphical representation that fits naturally with the proposed index, is also introduced. Finally, some examples with the analysis of well-known quantum algorithms degradation are given.
@article{arxiv.1610.05223,
title = {Characterizing error propagation in quantum circuits: the Isotropic Index},
author = {André L. Fonseca de Oliveira and Efrain Buksman and Ilan Cohn and Jesús García López de Lacalle},
journal= {arXiv preprint arXiv:1610.05223},
year = {2017}
}