Scientists photograph for the first time quantum entanglement "spooky"

• Albert Einstein's work partly predicted quantum entanglement: the idea that two particles can remain connected over vast distances in time and space.
• Einstein found the idea absurd and "spooky", but has since been proven by countless quantum physics experiments.
• No one had ever photographed entangled photons (pieces of light) until a research team did it recently with a high-tech laser experiment.
• Visit the Business Insider home page for more stories.

The black and white photo above is not very interesting. However, ghostly forms resembling eyes illustrate a strange phenomenon that so upset Albert Einstein that he died, incredulous.

The image represents the very first photograph of quantum entanglement, or spooky "couple".

"The image that we managed to capture is an elegant demonstration of a fundamental property of nature, seen for the very first time in the form of an image," said Paul-Antoine Moreau. , physicist at the University of Glasgow, in a statement. Press release.

Moreau led a team of researchers who managed to create the image, which the group published in a study Friday in the journal Science Advances.

Quantum entanglement 101

Quantum entanglement is the now well – documented idea that two tiny particles can be coupled and separated while remaining intimately and instantly connected over great distances.

According to the laws of physics, two particles can be entangled in a property or a binary state, of the yes or no type, such as the polarization of spin or phase. But this state remains unclear – or "superimposed" – until a particle is measured. Then, at the exact moment of observation, even if the particles are separated by light-years of space, the other particle takes the opposite state of its binoculars.

To understand this concept, imagine that each entangled particle was a box containing a cat. The cat inside would be both alive and dead at the same time, that is to say until someone opens one of the boxes. If the cat seen in a box was alive, then the cat in the other box should be dead (or vice versa).

Einstein thought that this teleportation effect was so absurd that he described it as "a phantasmagorical action at a distance".

"Einstein could not accept that," said Business Insider, J.C. Séamus Davis, a physicist at Cornell University who is studying quantum mechanics. "He basically went to his grave and did not accept that as a fact, but it has now been proven millions of times."

One of the latest studies proving it, published in February 2017, used a 600-year-old stellar light to show that two particles could not "cheat" at the time of entanglement and share a state before 39 to be measured.

How and why small particles can entangle makes no sense in the context of our daily lives. At very small scales, the universe seems to play according to different rules, many of which are paradoxical and defy reason. In some scenarios of quantum mechanics, for example, an effect does not always follow a cause; In fact, the effect can occur before its cause occurs.

Nobody should be blamed for being confused by quantum mechanics, Davis said, since "we have not evolved to understand" the theory and its counterintuitive ramifications.

"But the calculations, the predictions starting in the 1920s, have all turned out to be accurate," he said. "It is the most successful scientific theory of the human race."

In all these decades, however, no one has ever captured an image of entangled particles. So that's what Moreau and his colleagues decided to do.

How the entanglement was photographed for the first time

Light particles called photons can be entangled in a number of quantum properties. With their experience, however, the researchers chose a property called phase. The photons came out of an ultraviolet laser beam and then went through a special crystal known to entangle the phase of some photons.

Then, their experience divided the beam into two equal "arms" with a beam splitter or a semi-mirror glass. At this point, some of the photons that the crystal had entangled separated.

An arm of photons is passed through a filter to limit the particles to one of the four phases (a phase filter "actually measures the property of a photon, so that its partner will switch instantly). , the photons entered a very sensitive camera capable of detecting individual photons.The other arm led to a high speed trigger device for the camera.

The camera sensor recorded information only when two entangled photons – each from a separate arm – arrived at their respective detectors at the same time and with opposite phases. Over time, researchers constructed a patterned image of entangled photons hitting the camera.

The entangled photons that passed through the phase filter had to form four eye-shaped patterns, and that's exactly what the picture shows.

The experiment accumulates more and more evidence that what Einstein frightened was real, but also that entangled particles could be used in future science imaging applications, Moreau said.