abreaction

QuoteQuantum communication follows a similar idea, but individual photons act as the information carriers. A zero or one is encoded through the direction of the photon's polarization (i.e., their orientation in the horizontal and vertical directions or in a superposition of both states). Because photons behave according to quantum mechanics, their polarization cannot be measured without leaving detectable traces. Any attempt to intercept the message would be exposed.

Teleportation requires the photons to be nearly identical in properties such as timing and color. Producing such photons is hard because they come from separate sources.

At the University of Stuttgart, the researchers successfully teleported the polarization state of a photon from one quantum dot to a photon produced by a second quantum dot. One dot emits a single photon and the other generates an entangled photon pair. "Entangled" means the two photons share a single quantum state even when physically apart. One photon from the pair travels to the second quantum dot and interacts with its photon. When the two overlap, their superposition transfers the information from the original photon to the far-away partner of the entangled pair.

A key element of this achievement was the use of "quantum frequency converters," devices that adjust small frequency mismatches between photons.

https://www.sciencedaily.com/releases/2025/11/251129044516.htm