title: General Method for Constructing Local Hidden Variable Models for Entangled Quantum States.
abstract: Entanglement allows for the nonlocality of quantum theory, which is the resource behind device-independent quantum information protocols. However, not all entangled quantum states display nonlocality. A central question is to determine the precise relation between entanglement and nonlocality. Here we present the first general test to decide whether a quantum state is local, and show that the test can be implemented by semidefinite programing. This method can be applied to any given state and for the construction of new examples of states with local hidden variable models for both projective and general measurements. As applications, we provide a lower-bound estimate of the fraction of two-qubit local entangled states and present new explicit examples of such states, including those that arise from physical noise models, Bell-diagonal states, and noisy Greenberger-Horne-Zeilinger and W states.
authors.affiliation: ICFO-Institut de Ciencies Fotoniques, Barcelona Institute of Science and Technology, 08860 Castelldefels (Barcelona), Spain.
authors.forename: D
authors.initials: D
authors.lastname: Cavalcanti
authors.affiliation: ICFO-Institut de Ciencies Fotoniques, Barcelona Institute of Science and Technology, 08860 Castelldefels (Barcelona), Spain.|Departamento de Matemática, Universidade Federal de Minas Gerais, Caixa Postal 702, 31270-901 Belo Horizonte, Minas Gerais, Brazil.
authors.forename: L
authors.initials: L
authors.lastname: Guerini
authors.affiliation: Departamento de Matemática, Universidade Federal de Minas Gerais, Caixa Postal 702, 31270-901 Belo Horizonte, Minas Gerais, Brazil.
authors.forename: R
authors.initials: R
authors.lastname: Rabelo
authors.affiliation: ICFO-Institut de Ciencies Fotoniques, Barcelona Institute of Science and Technology, 08860 Castelldefels (Barcelona), Spain.|H. H. Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL, United Kingdom.
authors.forename: P
authors.initials: P
authors.lastname: Skrzypczyk