Quan­tum Tele­por­ta­ti­on over busy Inter­net Cables

Rese­ar­chers at Nor­thwes­tern Uni­ver­si­ty in Illi­nois have made an important advan­ce for the future of Quan­tum Com­mu­ni­ca­ti­on. In an expe­ri­ment, they have suc­cee­ded in trans­mit­ting Quan­tum Infor­ma­ti­on over a 30-kilo­met­re fiber optic cable that alre­a­dy car­ri­ed Inter­net traf­fic. This opens up the new pos­si­bi­li­ty of com­bi­ning Quan­tum Com­mu­ni­ca­ti­on with exis­ting com­mu­ni­ca­ti­on infra­struc­tu­re. The results of the expe­ri­ment have now been published in a paper.

A par­ti­cu­lar chall­enge was to tele­port Quan­tum Infor­ma­ti­on within a fiber optic cable that simul­ta­neous­ly trans­ports num­e­rous light par­tic­les from regu­lar data traf­fic; the sen­si­ti­ve pho­tons of Quan­tum Infor­ma­ti­on can easi­ly be dis­tur­bed by signals from con­ven­tio­nal Inter­net traf­fic. Prof. Dr. Prem Kumar’s team the­r­e­fo­re ana­ly­zed the scat­te­ring pat­terns of the light in the fib­re optic cables in order to iden­ti­fy a less fre­quent wave­length for the pho­tons of Quan­tum Com­mu­ni­ca­ti­on. With the help of spe­cial fil­ters, the noi­se of regu­lar tele­com­mu­ni­ca­ti­ons traf­fic could be fur­ther redu­ced. The results show that the Quan­tum Infor­ma­ti­on could be trans­mit­ted suc­cessful­ly and wit­hout inter­fe­rence even with hea­vy data traf­fic, enab­ling simul­ta­neous trans­mis­si­on of Quan­tum and clas­si­cal net­work appli­ca­ti­ons within a shared fiber optic infra­struc­tu­re.

The rese­ar­chers are now plan­ning to extend the expe­ri­ments to grea­ter distances and test the method in real fiber optic net­works. One aim is to demons­tra­te ent­an­gle­ment swap­ping. This invol­ves exchan­ging ent­an­gle­ments bet­ween seve­ral pho­ton pairs in order to increase the ran­ge of Quan­tum Ent­an­gle­ment in com­mu­ni­ca­ti­on net­works – an important step for the deve­lo­p­ment of dis­tri­bu­ted Quan­tum Appli­ca­ti­ons.

Source refe­rence: https://news.northwestern.edu/stories/2024/12/first-demonstration-of-quantum-teleportation-over-busy-internet-cables/