Semidefinite tests for quantum network topologies

Quantum networks play a major role in long-distance communication, quantum cryptography, clock synchronization, and distributed quantum computing. Generally, these protocols involve many independent sources sharing entanglement among distant parties that, upon measuring their systems, generate corre...

ver descrição completa

Detalhes bibliográficos
Autores: Åberg, Johan, Nery, Ranieri Vieira, Duarte, Cristhiano, Araújo, Rafael Chaves Souto
Tipo de documento: artigo
Estado:Versão publicada
Data de publicação:2020
País:Brasil
Recursos:Universidade Federal do Rio Grande do Norte (UFRN)
Repositório:Repositório Institucional da UFRN
Idioma:inglês
OAI Identifier:oai:repositorio.ufrn.br:123456789/63675
Acesso em linha:https://repositorio.ufrn.br/handle/123456789/63675
Access Level:Acceso aberto
Palavra-chave:Nonlocality
Não localidade
Quantum communication
Comunicação quântica
Quantum networks
Redes quânticas
Quantum simulation
Simulação quântica
Descrição
Resumo:Quantum networks play a major role in long-distance communication, quantum cryptography, clock synchronization, and distributed quantum computing. Generally, these protocols involve many independent sources sharing entanglement among distant parties that, upon measuring their systems, generate correlations across the network. The question of which correlations a given quantum network can give rise to remains almost uncharted. Here we show that constraints on the observable covariances, previously derived for the classical case, also hold for quantum networks. The network topology yields tests that can be cast as semidefinite programs, thus allowing for the efficient characterization of the correlations in a wide class of quantum networks, as well as systematic derivations of device-independent and experimentally testable witnesses. We obtain such semidefinite tests for fixed measurement settings, as well as parties that independently choose among collections of measurement settings. The applicability of the method is demonstrated for various networks, and compared with previous approaches.