Does the theory of relativity make teleportation impossible

Quantum physics: teleportation - the ghostly long-distance effect

Entanglement is at the beginning

In 1993, the research group headed by Charles Bennett from IBM thought publicly about how entanglement could be used for the teleportation of quantum states. In 1997, the physicist Anton Zeilinger was the first to put this idea into practice. For his experiment he used photons (light quanta). These can be interlaced by looking at them from opposite sides through a semitransparent mirror, a crystal made of barium borate (BaB2O4), sends. In a quarter of the cases, photons emerge on both sides of the mirror and are entangled with one another. They are polarized in opposite directions without knowing in which plane A and B vibrate. If the pair of photons AB is spatially separated from one another using physical tricks, the quantum transport experiment can begin.

“Information is an essential building block in the world. At some point we have to say goodbye to the naive realism according to which the world itself exists without our intervention and independent of our observation. " Anton Zeilinger, physicist

In his first attempt, Zeilinger entangled a third photon C with the sender photon A, which then assumed the quantum state of C with the opposite sign. At the same time, the distant receiver photon B changed its quantum state in the same way, as it were through telepathic forces. The quantum state of C had changed to B, thus a quantum teleportation had taken place.

This year a group of scientists in Innsbruck has succeeded in teleporting calcium ions over a distance of ten micrometers. The ions were cooled to a few millionths of a Kelvin (just above absolute temperature) and entangled with the help of lasers.

Also this year, Anton Zeilinger's group carried out the so-called Danube Experiment. They repeated their photon experiment at a distance of 630 meters through an 800 meter long fiber optic cable that they had pulled through the Danube culvert of the Wien Kanal Abwassertechnologien GmbH under the Danube. It was the first quantum teleportation outside of a laboratory. The fiber optic technology proved to be robust enough to withstand temperature fluctuations and vibrations. Because 50 percent of the photons could be teleported; the other half was absorbed somewhere along the line. After this success an attempt should be made to carry out quantum teleportation via satellites.

But it may take a few centuries before the visions of the science fiction authors are realized. Teleporting people will probably always remain a utopia. From today's perspective, there is not even a thought to send even a single bacterium. A person is made up of 1028 atoms. The atomic description of a human body alone overwhelms the imagination. To put it then into a quantum mechanical superposition does not seem possible. Heisenberg's uncertainty principle would cause great difficulties when beaming people. The creators of the "Star Trek" series solved the problem with the help of Heisenberg expansion joints. It is not that simple in the world of realities.

From "Beam me up, Scotty!" so we are still a long way off. In addition, the question arises as to whether it makes sense to first place a pile of matter and a teleportation receiver chamber on a desolate planet and then send the space travelers afterwards. Whether it seems worth striving at all to make human mobility truly limitless within the earth alone is more of a psychological question. However, quantum teleportation already has very concrete effects. Because entanglement is also the basis for the development of quantum computers and quantum cryptography.