Challenging preconceptions about Bell tests with photon pairs

Abstract

Motivated by very recent experiments, we consider a scenario "à la Bell" in which two protagonists test the Clauser-Horne-Shimony-Holt (CHSH) inequality using a photon-pair source based on spontaneous parametric down conversion and imperfect photon detectors. The conventional wisdom says that (i) if the detectors have unit efficiency, the CHSH violation can reach its maximum quantum value $2\sqrt{2}$. To obtain the maximal possible violation, it suffices that the source emits (ii) maximally entangled photon pairs (iii) in two well defined single modes. Through a non-perturabive calculation of non-local correlations, we show that none of these statements are true. By providing the optimal pump parameters, measurement settings and state structure for any detection efficiency and dark count probability, our results give the recipe to close all the loopholes in a Bell test using photon pairs.

5 pages, 2 figures,updated figure 1 and appendix

References in corpus (10)

• Bell nonlocality
• Device-independent security of quantum cryptography against collective attacks
• Random Numbers Certified by Bell's Theorem
• Bell violation with entangled photons, free of the fair-sampling assumption
• Detection-Loophole-Free Test of Quantum Nonlocality, and Applications
• Bell inequality violation with two remote atomic qubits
• Proposal for Implementing Device-Independent Quantum Key Distribution based on a Heralded Qubit Amplification
• Faithful entanglement swapping based on sum-frequency generation
• Device-Independent Quantum Key Distribution with Local Bell Test
• Cloning Entangled Qubits to Scales One Can See

Cited by in corpus (24)

• Advances in device-independent quantum key distribution
• Photonic verification of device-independent quantum key distribution against collective attacks
• Randomness extraction from Bell violation with continuous parametric down conversion
• Advantage distillation for device-independent quantum key distribution
• A Robust Mathematical Model for Clauser-Horne Experiments, With Implications for Rigorous Statistical Analysis
• Noisy pre-processing facilitating a photonic realisation of device-independent quantum key distribution
• Security of device-independent quantum key distribution protocols: a review
• Single-photon nonlocality in quantum networks
• Bell correlations in a split two-mode-squeezed Bose-Einstein condensate
• Randomness in post-selected events
• Comparing different approaches for generating random numbers device-independently using a photon pair source
• Towards practical device-independent quantum key distribution with spontaneous parametric downconversion sources, on-off photodetectors and entanglement swapping
• Heralded amplification of nonlocality via entanglement swapping for long-distance device-independent quantum key distribution
• Optimal conditions for Bell test using spontaneous parametric down-conversion sources
• Closing the detection loophole in tripartite Bell tests using the W state
• Automated design of quantum optical experiments for device-independent quantum key distribution
• Light-matter micro-macro entanglement
• Detection of Nonlocal Spin Entanglement by Light Emission from a Superconducting p-n Junction
• Optimal randomness generation from optical Bell experiments
• High fidelity GHZ generation within nearby nodes
• What is the minimum CHSH score certifying that a state resembles the singlet?
• Optimality of semiquantum nonlocality in the presence of high inconclusive rates
• Interplay of Quantum Resources in Nonlocality Tests
• A Tractable Protocol for Detection-Loophole-Free Bell Tests over Long Distances