
The experiment broke the previous distance record by more than three times.
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.
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.
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