Joshua Roebke in Scientific American:
Quantum mechanics is the consummate theory of particles, so it naturally describes measurements and interactions. During the past few decades, as computers have nudged the quantum, the theory has been reframed to encompass information, too. What quantum mechanics implies for measurements and interactions is notoriously bizarre. Its implications for information are stranger still.
One of the strangest of these implications refutes the material basis of communication as well as common sense. Some physicists believe that we may be able to communicate without transmitting particles. In 2013 an amateur physicist named Hatim Salih even devised a protocol, alongside professionals, in which information is obtained from a place where particles never travel. Information can be disembodied. Communication may not be so physical after all.
This past April, the early edition of a short article about Salih’s protocol appeared online in the Proceedings of the National Academy of Sciences. Most of the article’s 10 authors were members of the University of Science and Technology of China, at its branches in Shanghai and Hefei. The final author was Jian-Wei Pan, an eminent physicist who has also developed a constellation of satellites for communicating through quantum mechanics. He recently used this network for transmitting entangled particles over a distance of 1,200 kilometers.