Blog – Page 11078

For the first time, a team of physicists have successfully teleported a quantum state of a photon to a crystal over 25 kilometers away through a fiber optic cable. This effectively showed that the photon’s quantum state, not its composition, is important to the teleportation process. The team was led by Nicolas Gisin of the University of Geneva and the results were published in the journal Nature Photonics. With this new paper, Gisin’s team has successfully squashed the previous record they set a decade ago by teleporting a quantum state of a proton 6 kilometers.

The quantum state of the photon is able to preserve information under extreme conditions, including the difference between traveling as light or becoming stored in the crystal like matter. The photon’s state acts as information that can be teleported along great distances using the optical fiber, and can be stored within the crystal. This was achieved due to a phenomenon in quantum mechanics known as entanglement, where two particles have a correlation, despite the fact that they aren’t touching and transmitting information to one another.

To test this and ensure what they were observing was actually happening, one photon was stored in a crystal while the other was sent along optical fiber, over a distance of 25 kilometers. The photon that was sent along the optical fiber collides with a third photon, which was assumed to destroy them both. However, the information from the first photon was transferred to the third photon in the collision, like the transfer of energy when one billiard ball hits another. The information from the third photon came back to the crystal where it could be measured to ensure the information was preserved between the first and the second.

Einstein’s theory of relativity described gravity as the distortion of space and time—which bend and stretch based on the masses of objects within them as well as the energy released from the phenomena. A few years later however, we gained awareness of the confusing world of quantum physics as physicists discovered the existence of very small particles—which were later found to affect even the biggest, most powerful phenomena in the universe.

This led to the discovery of force-carrier particles, or bosons, behind three of the fundamental forces governing the universe: the electromagnetic field has photons, the strong nuclear force has gluons, and the weak force is carried by W and Z bosons. This leaves gravity out. Physicists hypothesize that, if the other three fundamental forces have a corresponding quantum theory, there must be a particle behind gravity too.

In an attempt to marry gravity with quantum theory, physicists came up with a hypothetical particle—the graviton. The graviton is said to be a massless, stable, spin-2 particle that travels at the speed of light.