EurekAlert August 12, 2024 Although progress has been reported in the generation of mutually entangled multi-photon quantum light states using free space apparatus, high-fidelity high-rate on-chip entanglement generation is important for future scalability. An international team of researchers (France, Italy, Brazil) used a bright quantum-dot based single-photon source to demonstrate the high-fidelity generation of 4-photon Greenberg-Horne-Zeilinger (GHZ) states with a low-loss reconfigurable glass photonic circuit. They reconstructed the density matrix of the generated states using full quantum-state tomography reaching an experimental fidelity and purity. The entanglement of the generated states was certified with a semi device-independent approach through the violation […]
Tag Archives: Quantum encryption
Single-photon source paves the way for practical quantum encryption
Phys.org March 23, 2022 Researchers in Australia have developed an on-demand way to generate photons with high purity in a scalable and portable system that operates at room temperature. They combined hexagonal boron nitride with a hemispherical solid immersion lens, which increases the source’s efficiency by a factor of six. They incorporated the single-photon source into a fully portable device that can perform QKD. They demonstrated that it could produce over ten million single photons per second at room temperature. The streamlined device is easier to use and much smaller than traditional optical table setups allowing the system to be […]
Space-borne quantum source to secure communication
Phys.org October 1, 2018 Researchers in Germany developed a remarkably stable yet powerful quantum source which can generate 300,000 entangled photon pairs per second when the light from a laser beam hits a non-linear crystal. The twinned light particles enable sensitive messages to be securely encrypted. The two photons’ polarization remains entangled no matter how far apart they may be. This allows two communicating parties to produce and share keys and immediately detect if a third-party attempts to intercept their communication. If an unauthorized party tampers with the message, the two photons disentangle to reveal that a hacking attempt is […]