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Schrödinger‑like charges in six‑molecule clusters point to new quantum components

Researchers from the University of Basel have published details of how electrons within a cluster of molecules interact with one another and can be controlled. Their findings pave the way for new approaches to developing quantum components and electronic circuits on the nanometer scale.

Electronic components are becoming increasingly small—so small, in fact, that quantum phenomena such as the superposition of states play a key role. Understanding this phenomenon is vital for the further development of molecular components and tiny circuits on the nanometer scale.

The behavior of paired electrons within molecules is already well understood. However, for radicals—molecules with an unpaired electron in their outer shell—there were no theoretical models describing interactions between molecules and the associated charge redistribution in small molecule clusters.

A new ‘library’ for Feynman integrals

Theoretical physicists at Johannes Gutenberg University Mainz (JGU) have developed a new method of ordering Feynman integrals. This critical step in making theoretical predictions for high-energy precision measurements has posed a major computational bottleneck until now.

Scientists in the research group of Professor Stefan Weinzierl from the PRISMA⁺⁺ Cluster of Excellence propose a solution to this longstanding challenge in new articles published in Physical Review Letters and Physical Review D. By ordering the integrals according to their intrinsic geometric properties, they can speed computation times by a factor of about 1,000.

“Feynman integrals are mathematical expressions that researchers must evaluate to make precise predictions,” said Weinzierl. “These are the first pillars for precise predictions for measurements at facilities like the Large Hadron Collider in Switzerland.” The number of these integrals varies from process to process, with some processes needing up to one million.

Scientists achieve all-electrical control of single-molecule quantum states

Quantum technologies promise revolutionary advances in computing, sensing and information processing. However, controlling individual quantum bits (qubits) at the atomic scale remains a major challenge because conventional approaches rely on magnetic fields, which are difficult to confine to a single molecule.

A research team at the Center for Quantum Nanoscience (QNS), led by Director Andreas Heinrich at the Institute for Basic Science (IBS), together with collaborators at the Karlsruhe Institute of Technology (KIT), has demonstrated that the quantum state of an individual magnetic molecule can instead be controlled electrically using a newly identified exchange-mediated mechanism. The study published in Nature Physics provides a new strategy for electrically controlling molecular quantum systems and could help pave the way for more scalable quantum technologies.

Magnetic molecules are considered attractive building blocks for future quantum technologies because they are only a few nanometers in size, can self-assemble into ordered structures and can be chemically tailored to possess desired quantum properties. These characteristics make them promising candidates for molecular quantum computing, quantum sensing and spintronic applications.

New computational imaging method cuts X-ray dose while preserving high resolution

Researchers have shown that it’s possible to take clear, high-resolution X-ray images using very little radiation. With more development, the new approach could eventually make medical X-ray diagnostics less risky and more accessible.

“While traditional X-ray imaging relies on enough X-ray photons reaching a detector to form a clear image, our approach uses computational techniques to reconstruct an image from fewer photons,” said research team leader Tiqiao Xiao from the Shanghai Advanced Research Institute, Chinese Academy of Sciences. “We were able to show the low-dose potential of this approach by achieving megapixel radiology with ultra-low-light.”

In Optica, the researchers demonstrate X-ray ghost images with nearly 2-megapixel resolution using only 0.48% of the X-ray photons typically required for X-ray imaging. The proof-of-concept study suggests that comparable X-ray image quality may eventually be achievable with far lower radiation doses than are used today.

Braided, exotic particles could build reliable, universal quantum computers

A truly useful quantum computer must be able to run any algorithm, with the same versatility an ordinary laptop offers. Physicists have now shown a new way to give a quantum computer exactly that flexibility, harnessing the capabilities of exotic quantum particles called non-Abelian anyons.

A team of scientists from the University of Chicago Pritzker School of Molecular Engineering (UChicago PME), Harvard, Stony Brook University and Quantinuum built and tested a complete toolkit of operations using non-Abelian anyons, proving for the first time the broad utility of this approach.

“We demonstrated a so-called universal gate set—meaning that if you store information in these emergent versions of quarks, and you move them around, you can do any quantum computation you might want to do,” said Ruben Verresen, assistant professor of molecular engineering at UChicago PME and a co-author of the new study published in Nature.

How ions flow like a liquid through a solid crystal

A research team led by the University of Osaka, working with the National Institute of Advanced Industrial Science and Technology (AIST), RIKEN and the Institute of Science Tokyo, has uncovered a fundamental mechanism behind superionic conduction, in which ions move rapidly through a solid while its crystalline framework remains intact.

Using a simple physical model, the researchers connected “sublattice melting” with cooperative and spatially heterogeneous ion transport. The findings offer a unified explanation for superionic conduction and could help guide the design of next-generation solid-state batteries.

The findings are published in the journal Proceedings of the National Academy of Sciences.

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