Toggle light / dark theme

Get the latest international news and world events from around the world.

Log in for authorized contributors

Twisted WSe₂ reveals elusive charge-neutral quantum modes

Quantum materials, materials with properties that are influenced by the laws of quantum mechanics, have attracted considerable attention over the past few decades. Their unique properties make these materials advantageous for the development of numerous cutting-edge technologies, including quantum computers, highly sensitive sensors and energy-efficient electronics.

In some quantum materials, electrons strongly interact with each other, producing what are known as correlated quantum phases, states in which the behavior of individual electrons is influenced by the behavior of other electrons. These phases can give rise to desirable properties or effects, including superconductivity, magnetism and collective excitations.

Researchers at University at California at Santa Barbara recently observed charge-neutral propagating collective spin-valley modes, coordinated waves of quantum behavior that carry no electrical charge and are difficult to probe experimentally, in the two-dimensional (2D) semiconductor twisted tungsten diselenide (WSe2).

Bioengineers condense protein engineering and testing to a single day

Proteins are critical to life—and to industry. There are countless proteins that could be engineered to treat and even cure serious diseases and cellular dysfunctions. Industrial applications are similarly promising, with proteins increasingly used as enzymes in food manufacturing and in consumer detergents.

While AI can help suggest improvements, each novel protein must still be created in the real world and tested for performance. It is a labor-intensive process that involves constructing the DNA instructions for each protein in yeast or bacteria and growing individual clones for protein production and testing. This can take many days for a single protein of interest and even longer if the protein needs to be tested in mammalian cells, a process that requires retrieving DNA from microbes for transfer to the mammalian cells.

In a new paper, Michael Z. Lin, a professor of neurobiology and of bioengineering in the schools of Engineering and Medicine, and graduate students, Yan Wu in bioengineering and Pengli Wang in chemical engineering, say they have condensed the time-intensive protein building and testing process to just 24 hours.

Dark lunar craters could host ultrastable lasers for moon navigation

They rank among the darkest and coldest places in the solar system: Hundreds of lunar craters, many of them at the moon’s south pole, never receive direct sunlight and lie in permanent shadow. That’s exactly why physicist Jun Ye and his colleagues suggest that these craters are the perfect place to build a critical component for an ultrastable laser.

On the moon, a highly stable laser—a source of coherent light that has a nearly unwavering frequency, or color—could provide a master time signal and offer GPS-like lunar navigation, said Ye, who is affiliated with both the National Institute of Standards and Technology (NIST) and JILA, a joint institute of NIST and the University of Colorado Boulder. Multiple copies of these lunar lasers could precisely measure the distances between objects and potentially detect exotic physics phenomena such as ripples in spacetime.

To construct a lunar laser, astronauts would first install a key component known as an optical silicon cavity —a block of silicon that permits only certain frequencies of light to bounce back and forth between mirrors on each end of the block. The distance between the two mirrors determines the frequencies that are allowed to resonate; for a highly stable optical cavity, that distance, and therefore those frequencies, does not vary.

Learning physics can derail some students: New research shows the best way to keep them on track

For many undergraduate students, exploring the complexities of physics for the first time, from wading through advanced mathematics, to absorbing information in a large lecture format, can be a daunting endeavor—one that dissuades many students from continuing their studies.

Educators have known for some time that students tend to learn these subjects better in hands-on, or “active learning,” environments—but some are more effective than others.

Reconfigurable Ge-Si photodetector achieves ultrahigh-speed data transmission using low-loss packaging

The rapid growth of large language models is placing increasing demands on data centers, where large volumes of data must be transferred efficiently between servers. Optical interconnects are essential for enabling this communication, but as data rates continue to rise, these systems must deliver higher bandwidth while maintaining low latency and energy efficiency. However, integrating electronic and photonic components remains challenging, as conventional approaches often introduce signal loss, limit interconnect density, and restrict scalability.

As reported in Advanced Photonics Nexus, Dr. Wei Chu and colleagues have developed a reconfigurable germanium–silicon photodetector using a low-loss integration strategy based on fan-out wafer-level packaging (FOWLP). This approach enables seamless integration of electronic integrated circuits and photonic integrated circuits on a single platform without the need for traditional wire bonding, reducing parasitic loss and improving signal integrity.

The system uses a dense network of fine metal interconnects, known as a redistribution layer (RDL), to connect components with high precision. This structure supports high interconnect density—exceeding 102 connections per square millimeter—while maintaining a low insertion loss of less than 0.3 dB/mm at 100 GHz. In addition, the use of benzocyclobutene as a low-dielectric insulating material reduces transmission loss and improves thermal stability for reliable high-frequency operation.

Prototype sets record for optical quantum information technology

Chinese scientists have developed a programmable quantum computing prototype called Jiuzhang 4.0 that has set a new world record for optical quantum information technology, according to a study published May 13 in the journal Nature.

Led by the University of Science and Technology of China (USTC), the team used the prototype to solve the Gaussian boson sampling problem at a speed more than 1054 times that of the world’s most powerful supercomputer, the study said.

The researchers said they manipulated and detected quantum states of up to 3,050 photons —a significant leap from the 255 photons achieved with the previous Jiuzhang 3.0.

The structure of water: Entropy determines whether ions stick

Water molecules do not simply swirl around in complete disorder; they can form certain preferred structures. This scientific fact is often presented in entirely unscientific ways. For example, when people speak of an alleged “memory of water” or of “water clusters” as a possible explanation for homeopathy, among other things.

All of this has been refuted. But even though water is not a magical information storage medium, its ability to form short-lived structures can have important consequences. This has now been shown in a study by TU Wien, in collaboration with the University of Vienna and the University of Oslo, as part of the Cluster of Excellence “MECS.” The team investigated how easily charged particles can be held at a surface—a question that is important in many areas, such as research on batteries, fuel cells, and biological membranes. The new results show that this can only be understood if one takes into account the structures that water forms on nanosecond timescales.

The research is published in the journal Science Advances.

How wasted infrared light could boost solar panels, night vision and 3D printing

Researchers at UNSW Sydney have developed a nanoscale device that converts low-energy infrared and red light into higher-energy visible light, a breakthrough that could eventually improve solar panels, sensing technologies, and advanced manufacturing systems.

Published in Nature Photonics, the research addresses a longstanding problem in photonics: how to stop energy from being lost before it can be used.

That mechanism allowed the device to achieve photon conversion efficiencies of 8.2%, among the strongest reported for this type of architecture.

Bilayer antiferromagnet reveals photocurrent that flips with magnetic state

In recent years, atomically thin materials—crystals only a few atoms thick—have attracted growing attention because they can exhibit physical properties that do not appear in conventional bulk materials. Among them, atomically thin magnetic materials are particularly intriguing, as they can host unconventional magnetic states and offer new possibilities for spin-based electronic technologies.

In a Nature Materials study, researchers investigated the photocurrent response of a bilayer atomically thin antiferromagnet. In this material, spins are aligned within each atomic layer, while the spin orientations of the top and bottom layers are opposite. Depending on the relative spin configuration between the two layers, the system exhibits two distinct antiferromagnetic (AFM) states.

To explore how these magnetic states interact with light, the researchers fabricated devices by attaching electrodes to bilayer samples and illuminated the center of the material, away from the electrodes. They measured both the zero-bias photocurrent and current-voltage characteristics under illumination.

AI shapes the design of the electron-ion collider

Artificial intelligence and machine learning are shaping major design and research decisions for the planned Electron-Ion Collider (EIC), a next-generation nuclear physics research facility that will collide electrons with protons or nuclei to probe matter’s structure.

The EIC—being built at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory in partnership with DOE’s Thomas Jefferson National Accelerator Facility (Jefferson Lab)—will reveal the inner structure of matter in unprecedented detail. It is the world’s first collider designed with AI and machine learning integrated into both its accelerator and detector systems.

“EIC is a new facility that can take advantage of AI and machine learning from the start,” said Tanja Horn, a professor of physics at The Catholic University of America, and co-chair of AI4EIC, a working group devoted to developing AI for the EIC. “A wide array of AI tools is now available—perfectly timed for the EIC.”

/* */