A method for reaching detection efficiencies necessary for optical loophole-free Bell experiments

Abstract

A method for preparing a loophole-free four-photon Bell experiments which requires a detection efficiency of 67% is proposed. It enables realistic detection efficiencies of 75% at a visibility of 85%. Two type-II crystals each down convert one correlated photon pair and we entangle one photon from one pair with one photon from the other pair on a highly transparent beam splitter. The entanglement selects two other conjugate photons into a Bell state. Wide solid angles for the conjugate photons then enable us to collect close to 100% of them. The cases when both photon pairs come from only one of the two crystals are successfully taken into account. Hardy's equalities are discussed.

RevTeX, 20 pages, 2figures, Author's URL http://m3k.grad.hr/pavicic

References in corpus (3)

• Interferometry with Two Pairs of Spin Correlated Photons
• Spin-correlated interferometry with beam splitters: preselection of spin-correlated photons
• Spin correlated interferometry for polarized and unpolarized photons on a beam splitter

Cited by in corpus (3)

• Optimal eavesdropping in quantum cryptography with six states
• Analysis of Bell inequality violation in superconducting qubits
• Retraction of "Near-Deterministic Discrimination of All Bell States with Linear Optics," Phys. Rev. Lett. 107, 080403 (2011) and Erratum Phys. Rev. Lett. 107, 219901 (2011)