Entanglement swapping

This effect happens without any previous direct interaction between particles A and D.[2][3] Entanglement swapping is a form of quantum teleportation.

By utilizing swapped entanglements between particles' pairs, it is possible to generate secure encryption keys that should be protected against eavesdropping.

Performing entanglement swapping at certain points acts like relaying information without loss.

[9][10] Bernard Yurke and David Stoler showed theoretically in 1992 that entanglement does not require interaction of the final measured particles.

[11] The term entanglement swapping was coined by physicists Marek Żukowski, Anton Zeilinger, Michael A. Horne, and Artur K. Ekert in their 1993 paper.

They refined the concept to show one can extend entanglement from one particle pair to another using a method called Bell state measurement.

[12] In 1998 Jian-Wei Pan working in Zeilinger's group conducted the first experiment on entanglement swapping.