First Measurement of Quantum Entanglement in Solid Materials Achieved

We have a groundbreaking method to measure quantum entanglement in solids, paving the way for significant advancements in quantum technology and fundamental physics.

Researchers face limitations in quantifying quantum entanglement—the phenomenon that correlates the behavior of distant quantum particles. The Bell test is one technique that assesses whether two particles are entangled or facilitates the intentional creation of entanglements in quantum computing setups.

However, detecting entangled particles within a material is far more complex. This capability is critical in developing advanced quantum computing and communication devices that rely on entanglement.

Allen Scheie from Los Alamos National Laboratory, along with his team, has dedicated over 50 years to refining this technology, and they have now confirmed its effectiveness.

“We have verified that it works flawlessly, and we’re taking steps to extend its application across various materials,” Scheie stated.

The innovative technique involves bombarding a sample material with neutrons and capturing them with a detector. Since the 1950s, studying the properties of these neutrons has allowed researchers to unveil the arrangement and behavior of quantum particles within substances. Scheie and his colleagues utilized this approach to calculate quantum Fisher information (QFI), a metric that indicates the minimum number of entangled quantum particles necessary to influence a neutron in a detected manner.

The research team applied their method to various magnetic materials, including well-documented crystals of potassium, copper, and fluorine. Team member Pontus Laurel emphasized that their findings closely aligned with computer simulations of the quantum architectures of these crystals, affirming the reliability of their new approach. “The experimental and theoretical predictions matched surprisingly well,” he stated.

Laurel added that while previous studies explored QFI and similar metrics as potential “witnesses to entanglement,” their group has established a clear, dependable, and broadly applicable measurement technique. Much of their effort focused on perfecting the nuances, enabling experiments with diverse materials, including those suitable for future device development.

Notably, their method remains effective irrespective of whether a robust mathematical model exists for the material, even when the samples are incomplete. “That’s the remarkable aspect: you can measure quantum Fisher information under any circumstances,” Scheie remarked. The research was presented at the American Physical Society Global Physics Summit on March 17th in Denver.

Within the next month, the researchers aim to enhance their methodology by measuring QFI (quantum equivalent at the transition point from water to ice) in materials approaching a phase transition. At this juncture, theoretical models often falter or predict skyrocketing entanglement, creating a prime opportunity for groundbreaking quantum discoveries, according to Scheie.