Scientists teleported an object into Earth’s orbit
Chinese scientists say they have succeeded in teleporting particle of photons from Earth to a satellite that orbits 1,400 kilometers (about 870 miles) away from our planet.
For many, however, teleportation evokes something much more exotic.
Is a world that was once confined to science fiction becoming a reality?
Somehow yes, but it is not likely that we can get to the office or a beach in the Bahamas at any time, unfortunately.
How does it work?
In short, teleportation is to transmit the state of an object instead of sending the object itself.
Some physicists put the example of a fax machine: send information about the marks on a sheet of paper instead of the paper itself.
The receiving fax machine obtains the information and applies it to the raw material in the form of paper that is already there.
But teleportation does not exist in the sense of the Star Trek series – the transfer of matter instantly from one place to another – which is how many instinctively see it.
Instead, what exists is based on a phenomenon known as a quantum entanglement.
What is the quantum entanglement?
The phenomenon arises when two particles are created at the same time and in the same place and therefore have the same existence.
This entanglement continues even as the photons separate. It means that if one of the photons changes, the other photon in the other position also changes.
Professor Sandu Popescu, of the University of Bristol, has been working on the quantum entanglement since the 1990s.
“Even then people were thinking about Star Trek, but we’re talking about sending the state of a single particle, not the billions of billions of particles that make up a person,” he says.
“If you think of a remote planet, you would first have to exchange billions of tangled pairs of particles and then you will have to send other information, which is not trivial. You should not be excited about that. ”
How can I teleport a particle?
Let’s go back to our two entangled particles. If a third particle interacts with the first particle, the change that occurs in it is reflected in its twin.
So the twin contains information about the third particle and effectively takes its existence.
Sounds easy, what’s the problem?
It has been impossible to create a long-distance link between two entangled particles because a tangled photon can travel only about 150 km through a fiber optic channel before being absorbed.
Researchers have long seen the potential of a satellite link because photons can travel more easily through space, but it has been difficult to transmit them through the Earth’s atmosphere, as variable atmospheric conditions can deflect particles.
What has the Chinese team achieved?
They created 4,000 pairs of photons per second in their laboratory in Tibet and fired one of the photons of each pair in a beam of light to a satellite called Micius in honor of a former Chinese philosopher.
Micius has a sensitive photon receiver that can detect the quantum states of individual photons sent from the ground.
The study, published online, says that it is the first link of this type for faithful and ultra-long distance quantum teleportation.
“I did not expect everything to work so quickly and so smoothly,” said Professor Anton Zeilinger of the University of Vienna, who was the teacher of Chinese scientist Pan Jianwei, the project leader.
If you can not teleport people, why is it exciting?
The main objective of quantum teleportation today is the creation of communications networks that can not be victimized by hackers.
“The laws of nature offer protection,” says Professor Popescu.
“If someone were to intercept information, you could detect it, because when you try to observe a quantum system you change it.”
The Chinese city of Jinan has already begun testing a secure network based on quantum technology and a network linking Beijing and Shanghai is under development with the so-called “trust nodes” , located every 100 km and in which the quantum signal Is measured and sent again.
“It is the first quantum internet, data rates are low so it is not useful for the current internet, but it is useful to refresh the quantum key used to send encrypted information,” says Zeilinger.
The quantum network could be used for sensitive financial or electoral information, says Professor Ian Walmsley of Oxford University.
“There are still major hurdles to overcome, but so do transformational changes,” he says.[arxiv.org]