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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