Work

When are correlations quantum?—verification and quantification of entanglement by simple measurements

Year: 2006

Type: article

Abstract: The verification and quantification of experimentally created entanglement by simple measurements, especially between distant particles, is an important basic task in quantum processing. When composite systems are subjected to local measurements the measurement data will exhibit correlations, whether these systems are classical or quantum. Therefore, the observation of correlations in the classical measurement record does not automatically imply the presence of quantum correlations in the system under investigation. In this study, we explore the question of when correlations, or other measurement data, are sufficient to guarantee the existence of a certain amount of quantum correlations in the system and when additional information, such as the degree of purity of the system, is needed to do so. Various measurement settings are discussed, both numerically and analytically. Exact results and lower bounds on the least entanglement consistent with the observations are presented. The approach is suitable both for the bi-partite and the multi-partite setting.

Source: New Journal of Physics

DOI: 10.1088/1367-2630/8/11/266

Authors: K M R Audenaert, M B Plenio

Institution: Imperial College London

Language: English

Topic: Quantum Information and Cryptography

Subfield: Artificial Intelligence

Field: Computer Science

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $2,610

Funders: Leverhulme Trust, Imperial College London, Engineering and Physical Sciences Research Council, Division of Mathematical Sciences