Quantum entanglement with the highest energy level

Experiments at the LHC, the huge particle accelerator at the European Laboratory for Particle Physics (CERN), have made it possible to observe quantum entanglement at an energy level higher than any other quantum entanglement known to exist on Earth. This quantum entanglement occurred between a particle of matter and another of antimatter. The results of these experiments open a fascinating new perspective on quantum physics.

Quantum entanglement is one of the most unusual phenomena in quantum physics. If two particles are quantum entangled, the state of one of them is intimately linked to that of the other, regardless of the distance that separates them. This phenomenon, which has no analogues in classical physics, has been observed in a wide range of quantum systems and has found several important applications, such as quantum cryptography and quantum computing. In 2022, Alain Aspect, John F. Clauser and Anton Zeilinger received the Nobel Prize in Physics for their revolutionary experiments with quantum-entangled photons. These experiments confirmed predictions about the manifestation of entanglement made by the late CERN theorist John Bell and pioneered quantum information science.

Quantum entanglement has remained largely unexplored at the high energies accessible at particle accelerators such as the Large Hadron Collider (LHC). In a new study, the scientific team of the ATLAS Collaboration has managed to observe at the LHC, for the first time, quantum entanglement between fundamental particles called top quarks and at higher energies than those achieved in any other known quantum entanglement.

Initially verified in September 2023, it has since been confirmed by a first and a second observation carried out by the CMS Collaboration, another of the groups of scientists working with LHC detectors.

Artist’s recreation of two quantumly entangled top quarks. (Image: CERN)

The ATLAS Collaboration team and the CMS team observed quantum entanglement between a top quark and its antimatter counterpart. The observations are based on a fairly new method that uses pairs of top quarks produced at the LHC as a system to study quantum entanglement.

The top quark is the heaviest known fundamental particle. It typically decays into other particles before it has time to combine with other quarks, transferring its spin and other quantum traits to its decay particles. Physicists observe and use these decay products to deduce the orientation of the top quark’s spin.

“Now we will be able to test the Standard Model of particle physics in new ways and look for signs of new physics that may lie beyond it,” says Patricia McBride, spokesperson for the CMS Collaboration, referring to the achievement of this quantum entanglement. between top quarks.

Those responsible for the experiment and subsequent analyzes present the technical details of all this in the academic journal Nature, under the title “Observation of quantum entanglement with top quarks at the ATLAS detector.” (Fountain: NCYT by Amazings)