Parity-encoding-based quantum computing with Bayesian error tracking

TL;DR

This paper introduces a photon-loss tolerant, resource-efficient measurement-based quantum computing protocol using parity encoding and Bayesian error tracking, improving fault-tolerance and reducing resource overhead in linear optical systems.

Contribution

It proposes a novel topological MBQC protocol with parity encoding, Bayesian error analysis, and graph optimization, enhancing fault-tolerance and resource efficiency in linear optical quantum computing.

Findings

Protocol is highly photon-loss tolerant.

Reduces resource overhead significantly.

Outperforms existing approaches in fault-tolerance.

Abstract

Measurement-based quantum computing (MBQC) in linear optical systems is promising for near-future quantum computing architecture. However, the nondeterministic nature of entangling operations and photon losses hinder the large-scale generation of graph states and introduce logical errors. In this work, we propose a linear optical topological MBQC protocol employing multiphoton qubits based on the parity encoding, which turns out to be highly photon-loss tolerant and resource-efficient even under the effects of nonideal entangling operations that unavoidably corrupt nearby qubits. For the realistic error analysis, we introduce a Bayesian methodology, in conjunction with the stabilizer formalism, to track errors caused by such detrimental effects. We additionally suggest a graph-theoretical optimization scheme for the process of constructing an arbitrary graph state, which greatly reduces its resource overhead. Notably, we show that our protocol is advantageous over several other existing approaches in terms of fault-tolerance, resource overhead, or feasibility of basic elements.