This discussion centers on the groundbreaking achievement of satellite-based distribution of entangled photon pairs over a distance of 1203 kilometers, surpassing the previous limit of approximately 100 kilometers. The experiment utilized two satellite-to-ground downlinks, with total lengths ranging from 1600 to 2400 kilometers. The results demonstrated a survival rate of two-photon entanglement and a violation of Bell inequality by 2.37 ± 0.09, confirming the effectiveness of this method under strict Einstein locality conditions. This advancement significantly enhances link efficiency compared to traditional telecommunication fiber methods.
PREREQUISITESQuantum physicists, telecommunications engineers, researchers in quantum networking, and anyone interested in the practical applications of quantum entanglement.
Source: http://science.sciencemag.org/content/356/6343/1140Abstract said:Long-distance entanglement distribution is essential for both foundational tests of quantum physics and scalable quantum networks. Owing to channel loss, however, the previously achieved distance was limited to ~100 kilometers. Here we demonstrate satellite-based distribution of entangled photon pairs to two locations separated by 1203 kilometers on Earth, through two satellite-to-ground downlinks with a summed length varying from 1600 to 2400 kilometers. We observed a survival of two-photon entanglement and a violation of Bell inequality by 2.37 ± 0.09 under strict Einstein locality conditions. The obtained effective link efficiency is orders of magnitude higher than that of the direct bidirectional transmission of the two photons through telecommunication fibers.