When it comes to weird quantum effects, none is weirder than quantum teleportation. Scientists can—and have—used the unique and complicated physics of quantum mechanics to instantaneously teleport small particles across great distances. Now, a Chinese team has broken the distance record by teleporting particles to a satellite in space.
When we talk about teleportation, we should be clear about exactly what that means. Nobody’s beaming people to space like in Star Trek. Instead, quantum teleportation is a complicated and delicate process involving sending information across space using entangled particles and reassembling it somewhere else.
We’ve written about quantum teleportation before, and a full explainer can be found here.
The hardest part of quantum teleportation is the entanglement. When two particles are entangled, they’re essentially ‘in sync’ with each other, and they’ll stay in sync no matter how far apart they are. But if one of the particles hits something else—like the air, or a beam of light, or literally anything—then the entanglement could be broken.
As you might imagine, keeping two particles entangled over large distances or for long periods of time is incredibly challenging. Until about a month ago, the farthest anyone had been able to separate entangled particles by was a few miles. But a Chinese team broke the record in June when they sent entangled particles to a satellite orbiting overhead, more than 300 miles away, while the particles they were entangled with remained on Earth.
Now, the same team has used those entangled particles to teleport photons from Earth to the satellite. Again, we need to be careful about what we mean when we say “teleport.” In this case, the scientists are sending information—they’re transferring information from a particle on the ground to a different particle in space, which takes on that information and essentially becomes the ground particle.
So, this isn’t Star Trek. This can’t be used to beam yourself into space or across the country, and faster-than-light communication is still impossible. But that doesn’t make this technology useless. Someday, quantum teleportation could be used as a form of encryption—because if anyone intercepts the communication it’ll mess up the entanglement—and to send results from quantum computers around the world.
Source: MIT Technology Review