The effect of component variations on the gate fidelity in linear optical networks

TL;DR

This paper examines how component variations affect gate fidelity in linear optical quantum computing, highlighting differences between implementations and proposing analysis methods for practical circuit design.

Contribution

It compares two implementations of the nonlinear sign gate, revealing their differing sensitivities to component variations and suggesting analysis techniques for optimizing circuit robustness.

Findings

Sensitivity to component variations differs significantly between implementations

Component variations impact gate fidelity in linear optical networks

Proposes routes for efficient circuit analysis using quantum parameter estimation

Abstract

We investigate the effect of variations in beam splitter transmissions and path length differences in the nonlinear sign gate that is used for linear optical quantum computing. We identify two implementations of the gate, and show that the sensitivity to variations in their components differs significantly between them. Therefore, circuits that require a precision implementation may benefit from additional circuit analysis of component variations to identify the most practical implementation. We suggest possible routes to efficient circuit analysis in terms of quantum parameter estimation.