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Researchers discover new self-assembled crystal structures

Using a targeted computational approach, researchers in the Department of Materials Science and Engineering at Cornell University have found more than 20 new self-assembled crystal structures, none of which had been observed previously.

The research, published in the journal ACS Nano under the title “Targeted Discovery of Low-Coordinated Crystal Structures via Tunable Particle Interactions,” is authored by Ph.D. student Hillary Pan and her advisor Julia Dshemuchadse, assistant professor of materials science and engineering.

“Essentially we were trying to figure out what kinds of new configurations we can self-assemble in simulation,” Pan said. “The most exciting thing was that we found new structures that weren’t previously listed in any crystal structure database; these particles are actually assembling into something that nobody had ever seen before.”

Researchers use structured light on a chip in another photonics breakthrough

In everyday life we experience light in one of its simplest forms—optical rays or beams. However, light can exist in much more exotic forms. Thus, even beams can be shaped to take the form of spirals; so-called vortex beams, endowed with unusual properties. Such beams can make dust particles to spin, just like they indeed move along some intangible spirals.

Light modes with such added structure are called “structured,” and even more exotic forms of structured light can be attained in artificial optical materials—metamaterials, where multiple come together and combine to create the most complex forms of light.

In their two recent works, published back-to-back in Science Advances, and Nature Nanotechnology, City College of New York researchers from Alexander Khanikaev’s group have created structured light on a silicon chip, and used this added structure to attain new functionalities and control not available before.

Team demonstrates quantum advantage on optimization problems with a 5,000-qubit programmable spin glass

Over the past decades, researchers and companies worldwide have been trying to develop increasingly advanced quantum computers. The key objective of their efforts is to create systems that will outperform classical computers on specific tasks, which is also known as realizing “quantum advantage.”

A research team at D-Wave Quantum Inc., a Canadian quantum computing company, recently created a new quantum computing system that outperforms classical computing systems on problems. This system, introduced in a paper in Nature, is based on a programmable spin glass with 5,000 qubits (the quantum equivalents of bits in classical computing).

“This work validates the original hypothesis behind , coming full circle from some seminal experiments conducted in the 1990s,” Andrew D. King, one of the researchers who carried out the study, told Phys.org.

‘Charge density wave’ linked to atomic distortions in would-be superconductor

What makes some materials carry current with no resistance? Scientists are trying to unravel the complex characteristics. Harnessing this property, known as superconductivity, could lead to perfectly efficient power lines, ultrafast computers, and a range of energy-saving advances. Understanding these materials when they aren’t superconducting is a key part of the quest to unlock that potential.

“To solve the problem, we need to understand the many phases of these materials,” said Kazuhiro Fujita, a physicist in the Condensed Matter Physics & Materials Science Department of the U.S. Department of Energy’s Brookhaven National Laboratory. In a new study just published in Physical Review X, Fujita and his colleagues sought to find an explanation for an oddity observed in a phase that coexists with the superconducting phase of a copper-oxide superconductor.

The anomaly was a mysterious disappearance of vibrational energy from the that make up the material’s crystal lattice. “X-rays show that the atoms vibrate in particular ways,” Fujita said. But as the material is cooled, the X-ray studies showed, one mode of the vibrations stops.

Researchers demonstrate electrical creation and control of antiferromagnetic vortices

A new study has shown for the first time how electrical creation and control of magnetic vortices in an antiferromagnet can be achieved, a discovery that will increase the data storage capacity and speed of next generation devices.

Researchers from the University of Nottingham’s School of Physics and Astronomy have used magnetic imaging techniques to map the structure of newly formed magnetic vortices and demonstrate their back-and-forth movement due to alternating electrical pulses. Their findings have been published in Nature Nanotechnology.

“This is an exciting moment for us, these magnetic vortices have been proposed as information carriers in next-generation memory devices, but evidence of their existence in antiferromagnets has so far been scarce. Now, we have not only generated them, but also moved them in a controllable way. It’s another success for our material, CuMnAs, which has been at the center of several breakthroughs in antiferromagnetic spintronics over the last few years,” says Oliver Amin.

Quantum Computing Algorithm Breakthrough Brings Practical Use Closer to Reality

Out of all common refrains in the world of computing, the phrase “if only software would catch up with hardware” would probably rank pretty high. And yet, software does sometimes catch up with hardware. In fact, it seems that this time, software can go as far as unlocking quantum computations for classical computers. That’s according to researchers with the RIKEN Center for Quantum Computing, Japan, who have published work on an algorithm that significantly accelerates a specific quantum computing workload. More significantly, the workload itself — called time evolution operators — has applications in condensed matter physics and quantum chemistry, two fields that can unlock new worlds within our own.

Normally, an improved algorithm wouldn’t be completely out of the ordinary; updates are everywhere, after all. Every app update, software update, or firmware upgrade is essentially bringing revised code that either solves problems or improves performance (hopefully). And improved algorithms are nice, as anyone with a graphics card from either AMD or NVIDIA can attest. But let’s face it: We’re used to being disappointed with performance updates.