Bell inequality violation by entangled single photon states generated from a laser, a LED or a Halogen lamp

Abstract

In single-particle or intraparticle entanglement, two degrees of freedom of a single particle, e.g., momentum and polarization of a single photon, are entangled. Single-particle entanglement (SPE) provides a source of non classical correlations which can be exploited both in quantum communication protocols and in experimental tests of noncontextuality based on the Kochen-Specker theorem. Furthermore, SPE is robust under decoherence phenomena. Here, we show that single-particle entangled states of single photons can be produced from attenuated sources of light, even classical ones. To experimentally certify the entanglement, we perform a Bell test, observing a violation of the Clauser, Horne, Shimony and Holt (CHSH) inequality. On the one hand, we show that this entanglement can be achieved even in a classical light beam, provided that first-order coherence is maintained between the degrees of freedom involved in the entanglement. On the other hand, we prove that filtered and attenuated light sources provide a flux of independent SPE photons that, from a statistical point of view, are indistinguishable from those generated by a single photon source. This has important consequences, since it demonstrates that cheap, compact, and low power entangled photon sources can be used for a range of quantum technology applications.

References in corpus (22)

• Random Numbers Certified by Bell's Theorem
• Generation of Hyperentangled Photons Pairs
• Generation of polarization entangled photon pairs and violation of Bell's inequality using spontaneous four-wave mixing in fiber loop
• Quantum Algorithms: Entanglement Enhanced Information Processing
• Bell-like inequality for spin-orbit separability of a classical laser beam
• Classical entanglement: Oxymoron or resource?
• Classically entangled optical beams for high-speed kinematic sensing
• Realization of All-or-nothing-type Kochen-Specker Experiment with Single Photons
• Classical wave-optics analogy of quantum information processing
• A feasible "Kochen-Specker" experiment with single particles
• Hybrid-Entanglement in Continuous Variable Systems
• Secure communication with single-photon two-qubit states
• Experiments towards Falsification of Noncontextual Hidden Variable Theories
• Two-way communication with a single quantum particle
• Quantum Cryptography Using Single Particle Entanglement
• Kochen-Specker theorem studied with neutron interferometer
• Quantum versus classical entanglement: eliminating the issue of quantum nonlocality
• Bell Inequalities for Quantum Optical Fields
• Quantum correlations in separable multi-mode states and in classically entangled light
• Generation of tunable entanglement and violation of a Bell-like inequality between different degrees of freedom of a single photon
• Hardy's paradox tested in the spin-orbit Hilbert space of single photons
• How many principles does it take to change a light bulb ... into a laser?

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• Entropy certification of a realistic QRNG based on single-particle entanglement
• Generation of quantum-certified random numbers using on-chip path-entangled single photons from an LED
• Experimental investigation of the relation between measurement uncertainties and non-local quantum correlations