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Updated: Aug 29, 2026

A Photonic System for Generating Unconditional Polarization-Entangled Photons Based on Multiple Quantum Interference
Published on: September 5, 2019
Entanglement formation and violation of Bell's inequality with a semiconductor single photon source
David Fattal1, Kyo Inoue, Jelena Vucković
1Quantum Entanglement Project, ICORP, JST, Ginzton Laboratory, Stanford University, Stanford, California 94305, USA.
Abstract:
We report the generation of polarization-entangled photons, using a quantum dot single photon source, linear optics, and photodetectors. Two photons created independently are observed to violate Bell's inequality. The density matrix describing the polarization state of the postselected photon pairs is reconstructed and agrees well with a simple model predicting the quality of entanglement from the known parameters of the single photon source. Our scheme provides a method to create no more than one entangled photon pair per cycle after postselection, a feature useful to enhance quantum cryptography protocols based on shared entanglement.
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