New Scientist: Two research teams have separately demonstrated the transfer of quantum information over several kilometers of fiber-optic cables. Both setups involved three hypothetical participants: two who want to securely share information via quantum-entangled particles, and a third who serves as an intermediary by intercepting and measuring the particles such that their quantum states get swapped and the information they carry is transferred. By varying the position of the participant who entangles the particles, the two research teams achieved slightly different results. Wolfgang Tittel of the University of Calgary in Alberta, Canada, and his colleagues sent quantum information over a distance of 6.2 km, while Jian-Wei Pan of the University of Science and Technology of China and his colleagues were able to extend the distance, to 12.5 km. The next step is to scale up such systems so they could provide secure communications over arbitrarily long distances.
Modeling the shapes of tree branches, neurons, and blood vessels is a thorny problem, but researchers have just discovered that much of the math has already been done.