Imperfect Linear Optical Photonic Gates with Number-Resolving Photodetection

TL;DR

This paper investigates how relaxing fidelity constraints in linear optical quantum gates can increase success rates, using numerical optimization to analyze two- and three-qubit entangling gates.

Contribution

It applies numerical optimization to study success rates of imperfect linear optical quantum gates, revealing predictable improvements as fidelity constraints are relaxed.

Findings

Success rates increase with relaxed fidelity constraints

Comparison of success rate improvements across different gates

Quantitative analysis of success rate behavior for system size

Abstract

We use the numerical optimization techniques of Uskov et al. [PRA 81, 012303 (2010)] to investigate the behavior of the success rates for KLM style [Nature 409, 46 (2001)] two- and three-qubit entangling gates. The methods are first demonstrated at perfect fidelity, and then extended to imperfect gates. We find that as the perfect fidelity condition is relaxed, the maximum attainable success rates increase in a predictable fashion depending on the size of the system, and we compare that rate of increase for several gates.