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Scientists develop predictive roadmap to boost performance in next-gen spintronics

Chiral 2D metal halide perovskites (MHPs) are among the most promising materials for future technologies that exploit the spin of electrons in spin-based optoelectronics, or spintronics, but getting them to perform consistently has proven difficult. Now scientists at Lawrence Berkeley National Laboratory (Berkeley Lab) have developed a data-driven approach that identifies and models key synthesis parameters to optimize their performance.

The difficulty stems in part from the sheer number of factors involved in making these materials. Although chiral 2D MHPs are low-cost and easy to fabricate as thin films, optimizing those films for optoelectronic technologies such as light-emitting diodes (LEDs) or photodetectors is a formidable challenge. Advanced spin-based optoelectronics use circularly polarized light to encode and transmit data. For several years, scientists have searched for ways to enhance these materials’ selectivity for circularly polarized light, but progress has been hampered by a reproducibility problem: Reported performance values for nominally the same material vary by more than two orders of magnitude across different laboratories.

A new study published in the journal Matter offers a roadmap for solving that problem. Scientist Carolin Sutter-Fella and her team at Berkeley Lab’s Molecular Foundry show how systematically tuning several “knobs” in the fabrication process—such as solvent choice, annealing temperature and film thickness—can reliably improve the material’s chiroptical properties, or its ability to interact with circularly polarized light.

Astrochemical model digs into the universe’s missing sulfur

Sulfur is one of the most abundant elements in the universe. If you peer into a diffuse interstellar cloud, you find loads of it—about the amount expected based on fusion patterns in the stars it was born in. However, if you look at a dense, cold molecular cloud—the kind where those stars actually form—it seems like 99% of the sulfur expected to be there is missing. Scientists have puzzled over this “missing sulfur problem” for decades, though a leading theory is that the element hides in icy dust grains, making it hard to detect.

A new paper published in Astronomy & Astrophysics from the Max Planck Institute for Extraterrestrial Physics and the Centro de Astrobiologia describes a new computer simulation model aimed at supporting the interpretation of laboratory results and testing our current understanding of sulfur evolution in interstellar ices.

The simulation was written in pyRate—a Python-based application that calculates how chemicals interact, especially between ice and gas phases. The paper marks the first successful model of the chemistry of a multicomponent interstellar ice analog with a rate-equation simulation. Scientists love “firsts,” but what does that actually mean in practice in this case?

Copper thin films reveal ballistic electron transport that could reshape future chip wiring

A joint research team has experimentally observed ballistic transport in single-crystalline copper thin films, demonstrating that ballistic transport is achievable in an industry-standard metal at interconnect-relevant dimensions. The study, titled “Ballistic transport in nanodevices based on single-crystalline Cu thin films,” was published in Nature Communications.

Ballistic transport refers to a phenomenon in which electrons travel along straight trajectories without scattering. Until now, this behavior has mainly been observed in special quantum materials such as graphene or semiconductor nanostructures. In copper, where electron scattering is pronounced, realizing ballistic transport has been considered practically impossible.

In this study, the team led by Professor Gil-Ho Lee of the Department of Physics at POSTECH, Professor Emeritus Se-Young Jeong of the School of Transdisciplinary Engineering at Pusan National University and Professor Seong-Gon Kim of the Department of Physics and Astronomy at Mississippi State University, experimentally demonstrated that ballistic transport can occur in structures with a thickness of 80 nm and a linewidth of 150 nm, dimensions comparable to those used in semiconductor interconnects.

Scientists measure hidden quantum forces that could power a new generation of pharmaceutical drugs

It’s one thing to design a pharmaceutical drug. It’s another to know if and why it actually works; not on paper or in a computer model, but inside the chaotic world of living systems, where proteins twist into shape, atoms constantly pull and push each other apart, and molecular interactions are the difference between health and disease.

For decades, scientists have known that these interactions are driven by hidden quantum forces. The problem is that, like working blindfolded, they’ve never been able to measure them directly in biological systems.

Now, that era of blindfolded work may be ending.

New bacteria-based cooling material could help electronics and EV batteries run cooler

Next-generation electronic devices like newer computers and other high-power devices require more energy to run. When they are working hard, the intense heat they generate can limit their performance and reliability. That’s why scientists are trying to find better and more sustainable materials to help cool devices down.

Weinan Xu, an assistant professor in the Department of Materials Science and Engineering at the University of Tennessee, Knoxville, has developed a novel concept for the fabrication and processing of thermal interface materials based on synergistic microbial biosynthesis, which is a way of making useful materials with the help of microbes like bacteria.

Thermal interface materials are specialized substances inserted between electronic and cooling devices to eliminate tiny air pockets so heat can move out of the device faster. By changing how the bacteria are grown and how the material is processed, the material’s ability to move heat, known as thermal conductivity, can be adjusted.

Scientists catch classical space-time crystals moving like Majorana quasiparticles

A research team from Hiroshima University, the University of Colorado, and other collaborators have demonstrated that space-time crystals—exotic structures that, under external drive, loop endlessly through both space and time—can be created using everyday liquid-crystal materials.

For the past decade, physicists have been fascinated by time crystals. Unlike normal crystals (such as salt or diamonds), which have repeating molecular patterns in space, time crystals have patterns that repeat at regular intervals in time. Previously, scientists believed these bizarre structures could exist only in highly complex, fragile quantum systems at near-absolute-zero temperatures, such as trapped ions or quantum simulators. However, in a collaborative study published in Nature Communications, researchers successfully created them in a classical, room-temperature liquid-crystal system.

To achieve this, the team took a liquid-crystal material—similar to the fluid used in smartphones and television screens—and doped it with ionic substances. They then applied a rhythmic, repeating electrical signal to the fluid. Using advanced computer models and optical microscopes, the researchers observed a surprising phenomenon known as period-doubling. Even though the electrical drive pumped energy into the fluid at a set internal rhythm, the liquid crystals spontaneously locked into a pattern that repeated only every two cycles of the electricity.

A new quantum computer sets a high watermark for accuracy. Are we on the verge of a big breakthrough?

In a laboratory in Broomfield, Colorado, 98 atoms are suspended in midair, held in place by electric fields and cooled to temperatures close to absolute zero.

Each atom is far smaller than anything the naked eye could ever see, yet each carries information in a form that has no counterpart in classical physics.

Together, they form Helios, a new quantum computer built by the British-American company Quantinuum. Quantum computers use the power of quantum mechanics, the rules that govern how physics operates at atomic and subatomic scales. Those that use Helios’ model of suspended atoms are known as trapped-ion.

Google releases new privacy controls for activity history, personalization

Google is rolling out new privacy controls for Search services and Google Play, giving you more control over saved history and personalized recommendations.

In an email titled “New privacy settings for Search services,” sent to users and seen by Bleeping Computer, Google said it is “updating our settings to give you even more control over saved history and personalized recommendations across Google Search services and Google Play.”

Google noted that Search services include “Search, Maps, Shopping, Hotels, Flights, Translate, and News,” and users will see the change in their Google Account in the next few days.

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