Pro­gress in Quan­tum Net­works

The deve­lo­p­ment of relia­ble and sca­lable Quan­tum Net­works is one of the grea­test chal­lenges in modern phy­sics. A key pre­re­qui­si­te for this is the use of ent­an­gled Quan­tum Par­tic­les: they enable the fast and tap-pro­of trans­mis­si­on of Quan­tum Infor­ma­ti­on over long distances. Howe­ver, the ent­an­gle­ment dis­ap­pears as soon as a pair of ent­an­gled par­tic­les are used for com­mu­ni­ca­ti­on, mea­ning the net­work is no lon­ger available for future tasks.

A rese­arch team from Rens­se­laer Poly­tech­nic Insti­tu­te (RPI) has been working for years on the deve­lo­p­ment of Quan­tum Net­works and published two new stu­dies in 2025 – in Phy­si­cal Review Let­ters in Janu­ary and Sci­ence Advan­ces in Febru­ary. The results bring the rea­liza­ti­on of con­nec­ted Quan­tum Sys­tems a signi­fi­cant step clo­ser. In the papers, the team pres­ents a new stra­tegy that allows new ent­an­gle­ment to be rep­le­nis­hed. This ensu­res that the net­work remains func­tion­al over time, enab­ling sta­ble com­mu­ni­ca­ti­on wit­hout over­loa­ding the sys­tem.

Par­ti­cu­lar­ly note­wor­t­hy is the use of a ‘mul­ti­plex­ing’ stra­tegy: ins­tead of rely­ing on just one trans­mis­si­on path, mul­ti­ple paths are used in par­al­lel. This red­un­dan­cy redu­ces noi­se and errors, ensu­ring that ent­an­gle­ment is relia­bly main­tai­ned even under dif­fi­cult con­di­ti­ons and as the net­wor­k’s com­ple­xi­ty grows. This pro­gress marks an important step toward lar­ge-sca­le Quan­tum Sys­tems, in which Quan­tum Infor­ma­ti­on can be pro­ces­sed and exch­an­ged secu­re­ly wit­hout the risk of eaves­drop­ping.

Source refe­ren­ces: https://www.newswise.com/articles/rpi-researchers-make-strides-toward-quantum-networking; https://www.science.org/doi/10.1126/sciadv.adt2404; https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.134.030803