“We have designed a kind of black box that allows you to switch from one type of quan­tum infor­ma­tion cod­ing to anoth­er thanks to the phe­nom­e­non of entan­gle­ment,” explains physi­cist Julian Lau­rat, one of the mem­bers of the LKB team.
Researchers at Lab­o­ra­toire Kastler Brossel (LKB) in France have cre­at­ed a con­vert­er that enables quan­tum devices based on dif­fer­ent sys­tems to com­mu­ni­cate. “We have designed a kind of black box that allows you to switch from one type of quan­tum infor­ma­tion cod­ing to anoth­er thanks to the phe­nom­e­non of entan­gle­ment,” explains physi­cist Julian Lau­rat, one of the mem­bers of the LKB team. Entan­gle­ment, the sub­ject of the 2022 Nobel Prize in Physics, is a pure­ly quan­tum phe­nom­e­non where­by two or more par­ti­cles can have a clos­er rela­tion­ship than that per­mit­ted by clas­si­cal physics. This means that if we deter­mine the quan­tum state of one of the par­ti­cles, we can instant­ly deter­mine the quan­tum state of the oth­er, regard­less of the dis­tance sep­a­rat­ing them. Once con­sid­ered a quirk of the quan­tum world, this “spooky action at a dis­tance”, as Albert Ein­stein called it, is now exploit­ed in quan­tum cryp­tog­ra­phy and com­mu­ni­ca­tion sys­tems, as well as in the sen­sors used to detect grav­i­ta­tion­al waves (a defor­ma­tion of the fab­ric of space-time that prop­a­gates at the speed of light)..