Curated by RSF Research Staff
Traversable wormhole, a key to quantum teleportation
Traversable wormholes have long been a source of fascination as a method of long distance transportation. This phenomenon has an interesting interpretation in the context of ER=EPR, or in few words related to space-time wormholes (ER) and quantum entanglement (EPR). And it might be related to quantum teleportation.
The so-called ER=EPR relationship was proposed by Juan Maldacena and Leonard Susskind in 2013. It means the Einstein Rosen bridge (ER, or wormhole), between two black holes is created by EPR-like (Einstein–Podolsky–Rosen, or quantum entanglement) correlations between the microstates of the two black holes. This ER=EPR equivalence was explored in more details in a precedent article.
Such traversable wormholes are really appealing but they would require matter that violates the null energy condition. This condition is stating that the stress-energy experienced by a light ray must not be negative. The problem is, this condition has to apply in physically reasonable classical theories even if, in quantum field theory, we already know that the null energy condition is false. However, a joint team from Harvard and Princeton has just shown how it is possible to render a wormhole traversable after gravitational backreaction without violating causality.
In a recent work, the team led by Ping Gao proposed a new approach to maintain opened a wormhole. This theoretical result was obtained by adding certain interactions that couple the two boundaries of eternal AdS-Schwarzschild resulting in a quantum matter stress tensor with negative average null energy. It shows that the Einstein-Rosen bridge of a BTZ black hole becomes slightly traversable after the addition of a two-boundary coupling. Doing this allows the wormhole to be open only for a small proper time in the interior region.
The traversable wormhole we found has an interesting interpretation in the context of ER=EPR. Maldacena and Susskind conjectured that any pair of entangled quantum systems are connected by an Einstein-Rosen bridge (the non-traversable wormhole). The crucial difference in our work is that we allow interaction between the entangled systems, which is assumed to be negligible in ER=EPR. What we have shown is that in this case the Einstein-Rosen bridge can open to become a traversable wormhole.
This discovery of the theoretical possibility of traversable wormholes could lead to multiple applications from the improvement in quantum telecommunication networks to a possible teleportation system in the future.