## Abstract

Quantum aided Byzantine agreement is an important distributed quantum algorithm with unique features in comparison to classical deterministic and randomized algorithms, requiring only a constant expected number of rounds in addition to giving a higher level of security. In this paper, we analyze details of the high level multi-party algorithm, and propose elements of the design for the quantum architecture and circuits required at each node to run the algorithm on a quantum repeater network (QRN). Our optimization techniques have reduced the quantum circuit depth by 44% and the number of qubits in each node by 20% for a minimum five-node setup compared to the design based on the standard arithmetic circuits. These improvements lead to a quantum system architecture with 160 qubits per node, space-time product (an estimate of the required fidelity) KQ ≈ 1.3 × 10 ^{5} per node and error threshold 1.1 × 10 ^{-6} for the total nodes in the network. The evaluation of the designed architecture shows that to execute the algorithm once on the minimum setup, we need to successfully distribute a total of 648 Bell pairs across the network, spread evenly between all pairs of nodes. This framework can be considered a starting point for establishing a road-map for light-weight demonstration of a distributed quantum application on QRNs.

Original language | English |
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Article number | 014011 |

Journal | Quantum Science and Technology |

Volume | 3 |

Issue number | 1 |

DOIs | |

Publication status | Published - 2018 Jan |

## Keywords

- Byzantine agreement
- distributed quantum algorithms
- quantum repeater network (QRN)

## ASJC Scopus subject areas

- Atomic and Molecular Physics, and Optics
- Materials Science (miscellaneous)
- Physics and Astronomy (miscellaneous)
- Electrical and Electronic Engineering