Scientists Teleport a Particle via the Internet—No Science Fiction Here!

Imagine two particles – two photons for example – created together in a special state. Once entangled, they become as “quantum twins”. Regardless of the distance which then separates them-a few millimeters or light years-a modification of the state of one instantly affects the other.

This does not mean that information travels faster than light, but rather than their states is fundamentally linked in an indivisible whole. This is called a non -local correlation.

Albert Einstein himself found it disturbing. He described this phenomenon as “SPOOOGY ACTION AT REMOTE” – Literally, a” ghostly action at a distance “. According to our intuition, two separate objects should not be able to influence each other without signal exchange. And yet, experiences have proven it on many times: this is exactly what quantum entanglement allows.

Today, this property is much more than theoretical curiosity: it has become the base of revolutionary technologies, such as quantum encryption, quantum computers … and, of course, quantum teleportation.

How to teleport a particle?

Quantum teleportation does not consist in moving a particle from point A to point B as in Star Trek. In reality, it is based on the instantaneous transfer of the quantum state from one particle to another, via an entangled system. In other words, we destroy the original particle, and another, elsewhere, adopts exactly the same properties.

Since the end of the 1990s, scientists have managed to teleport quantum states over short distances, under very controlled laboratory conditions, generally through dedicated optical fibers, sheltered from any interference. But the big question remained: can we do it in the real world, through ordinary communication networks?

The first quantum teleportation via public internet

This is precisely what researchers from the Northwestern University (United States) have accomplished. For the first time, a team managed to teleport a photon (light particle) over a distance of 29 kilometers, using the existing public internet infrastructure.

It may seem simple, but it is a real technical revolution.

Because quantum signals are extremely fragile: at the slightest contact with an external disturbance (parasitic light, vibrations, conventional signals …), they can lose their coherence, that is to say to behave like quantum objects. This is called the decor.

Until now, it was thought that it would be impossible to make a quantum signal coexist with the chaotic flow of information that passes through the Internet on a daily basis. But the researchers discovered a means of guiding the photons entangled in this digital hubbub, without them losing their coherence.

How did they succeed in this tour de force?

The team has developed an ingenious method: by very finely adjusting the way in which light (and therefore photons) spreads in optical fiber, they have reduced the risks of interference with the rest of the Internet traffic.

Imagine a biker in front of sneaking at full speed on a crowded highway: that's exactly what the quantum photon does in the middle of classic digital traffic. But by mastering its trajectory and speed, the researchers allowed this photon to reach its destination without losing its quantum state.

Result: teleportation worked, and the original photon state has been perfectly recreated 29 km away, via the Internet network.

Why is a major advance

It is not “fair” a successful experience: it is the beginning of a new era.

Until now, many have thought that to build a quantum internet, a new complete infrastructure would have to be erected, only dedicated to quantum signals. It would be extremely expensive and long to deploy.

But with this breakthrough, it becomes possible to have quantum data transit on the same networks as conventional data. The quantum Internet could therefore rely on our current infrastructure, drastically reducing technical and financial obstacles.

A future full of promises (and mysteries)

The quantum internet will not just be a “faster” version of the current Internet. It will be a revolution.

We are talking about inviolable cryptography, ultra-complex scientific models (such as global climate or the functioning of the brain), artificial intelligence that learn exponentially, and even-new forms of instant forms of instant forms on a planetary scale.

What this experience proves is that we no longer need to wait 50 years to lay the foundations for this new world. Quantum technology is starting to mingle with our daily lives, and this border between science fiction and reality becomes more and more vague.

Source: Optica