Optical cluster-state generation with unitary averaging

TL;DR

This paper presents a passive error averaging method using unitary averaging to generate high-fidelity optical cluster states, improving fidelity and Bell-state measurement success in fusion-based quantum computation architectures.

Contribution

It introduces a novel passive error averaging technique for optical cluster state generation that enhances fidelity and measurement success rates.

Findings

Enhanced average fidelity of cluster states through unitary averaging.

Improved Bell-state measurement success probability with imperfect BSM.

Method integrates seamlessly into existing FBQC architectures.

Abstract

Cluster states are the essential resource used in the implementation of Fusion-based quantum computation (FBQC). We introduce a method to generate high-fidelity optical cluster states by utilising the concept of unitary averaging. This error averaging technique is entirely passive and can be readily incorporated into the proposed PsiQuantum's FBQC architecture. Using postselection and the redundant encoding of Fusion gates, we observe an enhancement in the average fidelity of the output cluster state. We also show an improvement in the linear optical Bell-state measurement (BSM) success probability when the BSM is imperfect.