Physicists have distributed entangled photons between two ground stations separated by 1,203 kilometers (748 miles), using China's Micius satellite to more than ten times the previous record for entanglement distribution. The result, published in the journal Science, was led by Juan Yin, a physicist at the Science and Technology University of China in Shanghai.
The prior record for entanglement distribution reached only 100 kilometers (62 miles). Yin's team achieved the longer span by transmitting entangled photons from the satellite to several ground stations and using laser beams to prevent the light particles from getting lost as they traveled.
"We have demonstrated the distribution of two entangled photons from a satellite to two ground stations that are 1,203 kilometers [748 miles] apart," Yin explained in the research paper.
Quantum entanglement links two or more particles so that a change in one particle's state or properties instantaneously affects the other's, regardless of distance. The phenomenon is central to quantum computing, where quantum bits, or qubits, are used to store information.
The team wrote that the result "again confirms the nonlocal feature of entanglement and excludes the models of reality that rest on the notions of locality and realism." Long-distance entanglement distribution, they added, is "essential for the testing of quantum physics and quantum networks."
By showing that entanglement can be maintained across such a distance in space, the work points toward long-distance satellite quantum communication and possible quantum teleportation. Advances in quantum cryptography, which depend on extending entanglement, could affect how information is stored and transferred, with potential applications in communication security and payment systems.
Comments (0)