Research, Technology

Scientists have observed a new kind of quantum entanglement inside atomic nuclei

How is reality structured?And isn't it a permanent illusion? Physicists have been trying to answer these questions for decades, but the more they learn about the world, the weirder it gets. We know that matter is made up of tiny particles, and their interaction with each other can hardly be imagined. Take, for example, quantum superposition - according to this principle, particles can be in several states at the same time, but it is impossible to determine the result of their state before the moment of observation. Another fundamental principle of particle physics is quantum entanglement, according to which particles remain interconnected regardless of the distance between them. And although the "habitual" entanglement demonstrates the illusory nature of our reality, in early 2023, physicists from the Brookhaven National Laboratory (USA) reported its new form, discovered for the first time in history.

The Heavy Ion Collider (RHIC) tracks particles that result from collisions at the center of the detector.

New quantum entanglement

Fundamental principles of quantum mechanicsover and over again defy common sense, showing that reality is largely illusory. Fortunately, modern scientific instruments allow us to study in detail the shape and details inside atomic nuclei - the last was achieved by physicists at the US Brookhaven National Laboratory using the Relativistic Heavy Ion Collider (RHIC).

During the experiment, the researchers observed photons and gold ions as they accelerated around the collider and discovered a new type of quantum entanglement. But what is even more surprising is that scientists have also observed completely a new kind of quantum interference - an exotic effect, according to whicha particle like a photon can intersect its own trajectory while moving. The study of this effect is considered one of the most promising in modern physics. But first things first.

The laws by which the universe works are very strange.

Interesting fact
By studying a single entangled particle, scientists immediatelylearn about the other, even if they are millions of light-years apart. This strange connection between two (or more) particles occurs instantly, apparently violating the fundamental law of the universe. For this reason, Albert Einstein called entanglement "spooky" and "supernatural."

The RHIC collider is located in the institutionUS Department of Education and Science, where physicists can study the building blocks of nuclear matter—i.e. quarks and gluons that make up protons and neutrons. By colliding the nuclei of heavy atoms, such as gold, the researchers observed their movement in opposite directions around the collider at a speed close to the speed of light.

This means that the intensity of the collisionsbetween nuclei can "melt" the boundaries between individual protons and neutrons, allowing the study of quarks and gluons as they existed shortly after the Big Bang - before the formation of protons and neutrons, the paper says.

In fact, no one knows what quantum processes in the real world are responsible for the creation of space-time.

According to the principle of quantum entanglement,the aspects of one particle of an entangled pair depend on the aspects of the other particle, no matter how far apart they are (and what lies between them). These particles may be, for example, electrons or photons, and the aspect may be the state in which they are, for example, "rotation" in one direction or another. Physicists also want to know how quarks and gluons behave inside atomic nuclei in their current state in order to better understand the force that holds these building blocks of matter together.

More on the topic: Can quantum mechanics explain the existence of spacetime?

What happens inside atomic nuclei

For more information about particles and theirbehavior, physicists used "clouds" of photons (particles of light) that surrounded the accelerating ions around the RHIC collider - it was this method that allowed scientists to look inside the nuclei. If two gold ions passed each other at a close distance and did not collide, the photons surrounding one ion made it possible to study the internal structure of the other.

This two-dimensional visualization, as the results of the experiment showed, turned out to be revolutionary - the atomic nucleus looks too big compared to what was predictedtheoretical models. Moreover, polarized light made it possible to obtain detailed images of high-energy atomic nuclei and to examine the distribution of gluons (along the direction of the photon and perpendicular to it).

The results obtained also coincide with theoretical predictions of the distribution of gluons and measurements of the distribution of electric charge inside nuclei.

Read even more interesting articles about the latest discoveries in the field of quantum mechanics and high technologies on our channel in Yandex.Zen - articles that are not on the site are regularly published there

The new measurements also showed that momentum andthe energy of the photons themselves gets entangled with the momentum and energy of the gluons. Measuring only along the direction of the photon (or its unknown direction) leads to distortion of the image by photon effects. But measuring in the transverse direction avoids the "blurring" of light particles.

Now we can take a picture where we candistinguish the density of gluons at a given angle and radius. The resulting images are so accurate that we are starting to see a difference between where the protons are and where the neutrons are located inside these large nuclei.

Collider at Brookhaven National Laboratory USA

Measuring two particles with different physics chargesan interference pattern was observed, indicating that particles are entangled or synchronized with each other, even if these particles are different (including charge).

You might be wondering: Does quantum mechanics imply a plurality of worlds, or what is Everett's interpretation?

A new look at entanglement and interference

The authors of the work, published at the beginning of 2023 in the journal Science Advances, note that all the particles discussed in the work
exist not only as physical objects, but alsolike waves - like ripples on the surface of a pond, they hit a rock (mathematical "wave functions") and can interfere, amplifying or canceling each other out.

Interference occurs between two wavefunctions of identical particles, but without entanglement (between two dissimilar particles) this interference would be impossible. This is how quantum mechanics gets weirder and weirder - a new experiment has shown that quantum entanglement exists between dissimilar particles.

See also: Can photons move forward and backward in time?

“This method is similar to the positron emissiontomography (PET scan) to see what is happening inside the brain and other parts of the body,” explains James Daniel Brandenburg from the Brookhaven Laboratory (USA). In recent years, scientists have paid more and more attention to quantum mechanics. One of the reasons for the increased attention is the creation of powerful new means of communication and computers.

Entanglement of quantum states is a reality.

Researchers also intend to conduct newmeasurements at RHIC with heavier particles (to test other possible quantum entanglement scenarios). Read more about what discoveries in 2022 had a huge impact on our knowledge about the structure of the Universe, we told here, do not miss it!