Long distance secure quantum communication. The full article – https://www.osapublishing.org/optica/abstract.cfm?uri=optica-7-3-238
Read the full article at: https://science.sciencemag.org/content/368/6489/382.5?utm_campaign=ec_sci_2020-04-23&et_rid=54900386&et_cid=3300291