Phys.org November 28, 2018
For practical long-distance quantum communication room-temperature atomic vapours are important. Atomic motion has so far limited the single-excitation lifetime in such systems to the microsecond range. Researchers in Denmark have demonstrated that lifespan of the quantum state at room temperature can be extended to about a quarter of a millisecond. They used a small glass container, filled with Cesium atoms, in which they were able to load, store and retrieve single photons from, the quantum states necessary for the repeater. This technique improves the life span of the quantum states at room temperature a hundred times…read more. Open Access TECHNICAL ARTICLE
When distributing entanglement between sender A and receiver B, the communication line is segmented by inserting quantum repeaters. Credit: Niels Bohr Institute