Quantum breakthrough as satellite ‘calls’ Earth from orbit
- Scientists in China used ‘quantum satellite’ to send entangled photons 1,200 km
- The satellite produces entangled photon pairs which form an encryption key
- These photons will theoretically remain linked over great distances
- This means that any attempts to listen in will be detected on the other side
By Cheyenne MacDonald
In a major breakthrough for quantum teleportation, scientists in China have
successfully transmitted entangled photons farther than ever before,
achieving a distance of more than 1,200 km (745 miles) between
suborbital space and Earth.
Entangled photons theoretically maintain
their link across any distance, and have potential to revolutionize
secure communications – but, scientists have previously only managed to
maintain the bond for about 100 km (62 miles).
Using the ‘quantum satellite’ Micius, the
scientists were able to communicate with three ground stations in China,
each more than 1,000 km (621 miles) apart.
In
quantum physics, entangled particles remain connected so that actions
performed by one affects the behaviour of the other, even if they are
separated by huge distances. This is illustrated in the artist’s
impression
The 1,300 pound craft satellite is equipped with a laser beam, which the scientists subjected to a beam splitter.
This gave the beam two distinct polarized states.
One of these beams was then used to transmit entangled particles, and the other used to receive the photons.
Pairs of entangled photons fired to ground stations can then form a ‘secret key.’
Theoretically, any attempts to breach this type of communication would be easily detectable.
The satellite launched from Jiuquan
Satellite launch Center last year, and the new findings mark a promising
step forward in the two-year mission prove successful, which could be
followed by a fleet of others if all goes well, according to Nature.
To overcome the complications of
long-distance quantum entanglement, scientists often break the line of
transmission up, creating smaller segments that can then repeatedly
swap, purify, and store the information along the optical fiber,
according to the American Association for the Advancement of Science.
Or, as in this case, they can use lasers and satellites.
What is quantum Entanglement?
In quantum physics, entangled particles remain connected so that actions performed by one affects the behaviour of the other, even if they are separated by huge distances.This means if you measure, ‘up’ for the spin of one photon from an entangled pair, the spin of the other, measured an instant later, will be ‘down’ – even if the two are on opposite sides of the world.Entanglement takes place when a part of particles interact physically. For instance, a laser beam fired through a certain type of crystal can cause individual light particles to be split into pairs of entangled photons.The theory that so riled Einstein is also referred to as ‘spooky action at a distance’. Einstein wasn’t happy with theory, because it suggested that information could travel faster than light.
The researchers sought to prove that particles can remain entangled across great distances – in this case, nearly 750 miles.
Earlier efforts to demonstrate quantum
communication have shown this can be done up to just over 180 miles, and
scientists hope that transmitting the photons through space will push
this even farther.
When travelling through air and optical
fibres, protons get scattered or absorbed, Nature explains, posing
challenges to the preservation of the fragile quantum state.
But, photons can travel more smoothly through space.
In
a major breakthrough for quantum teleportation, scientists in China
have successfully transmitted entangled photons farther than ever
before, achieving a distance of more than 1,200 km (745 miles) between
suborbital space and Earth
Achieving quantum
communication at such distances would enable the creation of secure
worldwide communications networks, allowing two parties to communicate
using a shared encryption key.
In quantum physics, entangled particles
remain connected so that actions performed by one affects the behaviour
of the other, even if they are separated by huge distances.
So, if someone were to attempt to listen in on one end, the disruption would be detectable on the other.
Over the course of the two-year mission,
the researchers in China will conduct a Bell test to prove the existence
of entanglement at such a great distance.
And, they will attempt to ‘teleport’
quantum states, according to Nature, meaning the quantum state of the
photo will be rebuilt in a new location.
Researchers from Canada, Japan, Italy, and
Singapore have also revealed plans to conduct quantum experiments in
space, including one proposed aboard the International Space Station.
This experiment would attempt to create a reliable and efficient means for teleportation.
By achieving quantum teleportation, the researchers say they could create a telescope with an enormous resolution.
‘You could not just see planets,’ Paul
Kwiat, a physicist at the University of Illinois at Urbana–Champaign
involved with the Nasa project, ’but in principle read licence plates on
Jupiter’s moons.
’
This article (Quantum breakthrough as satellite ‘calls’ Earth from orbit) was originally published on Daily Mail and syndicated by The Event Chronicle.
