A record-breaking distance has been achieved in the bizarre world of quantum
teleportation, scientists say.
The scientists teleported photons (packets of light) across a spool of fiber
optics 63 miles (102 kilometers) long,
four
times farther than the previous record. This research could one day lead to
a "quantum Internet" that offers next-generation encryption, the
scientists said.
Teleporting an object from one point in the universe to another without it
moving through the space in between may sound like science fiction pulled from
an episode of "Star Trek," but scientists have actually been
experimenting with "quantum teleportation" since 1998.
Quantum teleportation depends on
capturing the fundamental details of an object — its "quantum states"
— and instantly transmitting that information from one area to another to
recreate the exact object someplace else.
Quantum teleportation relies on the
strange nature of quantum physics, which finds that the fundamental building
blocks of the universe can essentially exist in two or more places at once.
Specifically, quantum teleportation
relies on an odd phenomenon known as "quantum entanglement,"
in which subatomic particles can become linked and influence each other instantaneously,
regardless of how far apart they are. Scientists cannot distinguish the state
of either particle until one is directly measured, but because the particles
are connected, measuring one instantly determines the state of the other.
Currently, physicists can't instantly transport matter
(say, a human), but they can use quantum teleportation to beam information from
one place to another. In a recent experiment, scientists at the National
Institute of Standards and Technology (NIST) were able to teleport photons
farther across an optical fiber than ever before.
"What's exciting is that we
were able to carry out quantum teleportation over such a long distance,"
study co-author Martin Stevens, a quantum optics researcher at the NIST in
Boulder, Colorado, told Live Science.
The new distance record was set
using advanced single-photon detectors made of superconducting wires of
molybdenum silicide that were about 150 nanometers (or billionths of a meter)
wide and cooled to about minus 457 degrees Fahrenheit (minus 272 degrees
Celsius), or about 1 degree above absolute zero.
The experiment involved a near-infrared wavelength commonly used in
telecommunications, the researchers said.
"Only about 1 percent of
photons make it all the way through 100 kilometers (60 miles) of fiber,"
Stevens said in a statement. "We never could have done this experiment
without these new detectors, which can measure this incredibly weak
signal."
The detectors used in this new
experiment could record more than 80 percent of arriving photons, according to
the scientists. In comparison, the previous record-holder had detectors that
operated with about 75 percent efficiency at best. Moreover, the new experiment
detected 10 times fewer stray photons than the previous record-holder.
Prior research did achieve quantum
teleportation over longer distances over open air — a span of 89 miles (144
kilometers) between the two Canary Islands of La Palma and Tenerife, located
off the northwest coast of Africa.
"However, the experiment at the
Canary Islands involved a telescope on top of one mountain and a telescope on
top of another mountain, with the telescopes pointed at each other at night,
since background light during the day would interfere with the
experiment," Stevens said. "If you wanted quantum teleportation in
the real world — say, from one city to another — you might not necessarily have
a direct line-of-sight between two locations, and you wouldn't want to be
limited to working at night, so fiber optics might be more feasible."
Quantum teleportation could enable
the development of a "quantum Internet" that allows messages to be sent more securely,
Stevens said.
"A quantum Internet could allow
you to establish communications channels that are much more secure than what we
have with the standard encryption protocols we use everyday nowadays,"
Stevens said.
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