Quantum teleportation just happened. While this doesn’t mean a Star Trek transport deck anytime soon (if ever), it could mean a quantum leap in computing.
What Chinese scientists actually teleported over hundreds of miles using a quantum satellite wasn’t a phaser or Mr. Spock, but a photon. Quantum teleportation isn’t the same phenomenon you see in sci-fi. There is no sudden materializing on the surface of an alien planet or beaming the shimmering figures of Starfleet officers back on board. Technically, it isn’t bona fide teleportation because what the scientists are transmitting is not an object but information about it that only two observers can access. What this could mean for future methods of data encryption is that they will go boldly where no encryption technology has gone before, even if that future is still light-years away.
“This work establishes the first ground-to-satellite up-link for faithful and ultra-long-distance quantum teleportation, an essential step toward global-scale quantum internet,” stated the researchers in a new paper.
Now, to translate that.
In quantum physics, it is impossible to determine the exact properties of a photon until the human eye actually observes it. The consequence is called entanglement. Meaning, probabilities of what the photon actually looks like are the only thing we have to work with until we actually see it. When China launched the satellite Micius last summer, it was designed to use the principles of quantum mechanics to test extreme long-distance communications. Initial results proved they had succeeded in entangling particles over immense distances that had never before been reached with this kind of experiment.
If entanglement entangles your brain, think of it this way. Imagine being assigned to study one of two different photons, Photon A or Photon B, while another researcher has been assigned to the other one. Neither of you know which one you have. Quantum mechanics can only tell you the probability that you have one or the other. Enter entanglement, which says both photons are Photon A and Photon B at the same time until the suspense gets to you enough to look and see which one you have. Now it gets even weirder. Seeing your photon means your partner’s photon automatically takes on the properties of the other option left.
Got that? Quantum teleportation is like randomly handing out Photon A and Photon B to one person on Earth and another in a satellite. However, there is another secret Photon B on the ground, which scientists want to “teleport” to the satellite without giving away the photon’s identity. With an entangled link established, those back at mission control only have to look at their photons and call the satellite to report that the photons are either the same or different. If both Photon Bs are on the ground, the message would be “same.” The observer on the satellite confirms that the entangled Photon A is in space, which means entangled Photon B must be on the ground and the secret photon has to be the other Photon B.
Lasers and crystals on the Chinese satellite functioned the same way by giving light particles one of two different polarization states before the particles were entangled and separated up to 800 miles. Researchers then used their entanglement links to transmit photon secrets.
“If your goal is to create some kind of quantum cryptography network, then using a [quantum satellite] to do it would be a significant step forward,” said physicist Matthew Leifer.
There are still glitches to work out before we can actually zap encrypted data through a satellite network. The signals are nowhere near hi-fi yet. Millions of photons were sent into space, and while results were only confirmed for just over 900 of them, to think that this could someday lead to global quantum internet is mind-blowing.