Enhanced multiqubit phase estimation in noisy environments by local encoding

The first generation of multiqubit quantum technologies will consist of noisy, intermediate-scale devices for which active error correction remains out of reach. To exploit such devices, it is thus imperative to use passive error protection that meets a careful trade-off between noise protection and...

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Bibliographic Details
Authors: Proietti, Massimiliano, Ringbauer, Martin, Graffitti, Francesco, Barrow, Peter, Pickston, Alexander, Kundys, Dmytro, Cavalcanti, Daniel, Aolita, Leandro, Araújo, Rafael Chaves Souto, Fedrizzi, Alessandro
Format: article
Status:Published version
Publication Date:2019
Country:Brasil
Institution:Universidade Federal do Rio Grande do Norte (UFRN)
Repository:Repositório Institucional da UFRN
Language:English
OAI Identifier:oai:repositorio.ufrn.br:123456789/30208
Online Access:https://repositorio.ufrn.br/handle/123456789/30208
Access Level:Open access
Keyword:Quantum channels
Quantum error correction
Quantum metrology
Quantum optics
Quantum parameter estimation
Resource theories
Description
Summary:The first generation of multiqubit quantum technologies will consist of noisy, intermediate-scale devices for which active error correction remains out of reach. To exploit such devices, it is thus imperative to use passive error protection that meets a careful trade-off between noise protection and resource overhead. Here, we experimentally demonstrate that single-qubit encoding can significantly enhance the robustness of entanglement and coherence of four-qubit graph states against local noise with a preferred direction. In particular, we explicitly show that local encoding provides a significant practical advantage for phase estimation in noisy environments. This demonstrates the efficacy of local unitary encoding under realistic conditions, with potential applications in multiqubit quantum technologies for metrology, multipartite secrecy, and error correction