Aurelia Butler

Researchers at the University of Gothenburg have made light-powered gears on a micrometer scale. This paves the way for the smallest on-chip motors in history, which can fit inside a strand of hair.
Gears are everywhere – from clocks and cars to robots and wind turbines. For more than 30 years, researchers have been trying to create even smaller gears in order to construct micro-engines. But progress stalled at 0.1 millimeters, as it was not possible to build the drive trains needed to make them move any smaller.
Researchers from Gothenburg University, among others, have now broken through this barrier by ditching traditional mechanical drive trains and instead using laser light to set the gears in motion directly.
Gears powered by light
In their new study, the researchers shows that microscopic machines can be driven by optical metamaterials – small, patterned structures that can capture and control light on a nanoscale. Using traditional lithography, gears with an optical metamaterial are manufactured with silicon directly on a microchip, with the gear having a diameter of a few tens of micrometers. By shining a laser on the metamaterial, the researchers can make the gear wheel spin. The intensity of the laser light controls the speed, and it is also possible to change the direction of the gear wheel by changing the polarization of the light.
The researchers are thus close to creating micromotors.
A new way of thinking
“We have built a gear train in which a light-driven gear sets the entire chain in motion. The gears can also convert rotation into linear motion, perform periodic movements and control microscopic mirrors to deflect light,” says the study’s first author, Gan Wang, a researcher in soft matter physics at the University of Gothenburg.

The ability to integrate such machines directly onto a chip and drive them with light opens up entirely new possibilities. Since laser light does not require any fixed contact with the machine and is easy to control, the micromotor can be scaled up to complex microsystems.
“This is a fundamentally new way of thinking about mechanics on a microscale. By replacing bulky couplings with light, we can finally overcome the size barrier,” says Gan Wang.
Cell size
With these advances, researchers are beginning to imagine micro- and nanomachines that can control light, manipulate small particles or be integrated into future lab-on-a-chip systems. A gear wheel can be as small as 16-20 micrometers, and there are human cells of that size. Medicine is a field that is within reach, believes Gan Wang.
“We can use the new micromotors as pumps inside the human body, for example to regulate various flows. I am also looking at how they function as valves that open and close.” More

Scientists at NYU Abu Dhabi (NYUAD) have developed an artificial intelligence (AI) model that can forecast solar wind speeds up to four days in advance, significantly more accurately than current methods. The study is published in The Astrophysical Journal Supplement Series.
Solar wind is a continuous stream of charged particles released by the Sun. When these particles speed up, they can cause “space weather” events that disrupt Earth’s atmosphere and drag satellites out of orbit, damage their electrons, and interfere with power grids. In 2022, a strong solar wind event caused SpaceX to lose 40 Starlink satellites, showing the urgent need for better forecasting.
The NYUAD team, led by Postdoctoral Associate Dattaraj Dhuri and Co-Principal Investigator at the Center for Space Science (CASS) Shravan Hanasoge, trained their AI model using high-resolution ultraviolet (UV) images from NASA’s Solar Dynamics Observatory, combined with historical records of solar wind. Instead of analyzing text, like today’s popular AI language models, the system analyzes images of the Sun to identify patterns linked to solar wind changes. The result is a 45 percent improvement in forecast accuracy compared to current operational models, and a 20 percent improvement over previous AI-based approaches.
“This is a major step forward in protecting the satellites, navigation systems, and power infrastructure that modern life depends on,” said Dhuri, lead author of the study. “By combining advanced AI with solar observations, we can give early warnings that help safeguard critical technology on Earth and in space.”
The breakthrough demonstrates how AI can solve one of space science’s toughest challenges: predicting the solar wind. With more reliable forecasts, scientists and engineers can better prepare for space weather events, strengthening resilience against disruptions to critical infrastructure.
NYU Abu Dhabi has established more than 90 faculty labs and projects, producing over 9,200 internationally recognized research publications. Times Higher Education ranks NYU among the world’s top 35 universities, making NYUAD the highest globally ranked university in the UAE. More

Spintronics, or spin-electronics, is a revolutionary approach to information processing that utilizes the intrinsic angular momentum (spin) of electrons, rather than solely relying on electric charge flow. This technology promises faster, more energy-efficient data storage and logic devices. A central challenge in fully realizing spintronics has been the development of materials that can precisely control electron spin direction.
In a groundbreaking development for spin-nanotechnology, researchers led by Professor Young Keun Kim of Korea University and Professor Ki Tae Nam of Seoul National University have successfully created magnetic nanohelices that can control electron spin. This technology, which utilizes chiral magnetic materials to regulate electron spin at room temperature, has been published in Science.
“These nanohelices achieve spin polarization exceeding ~80% — just by their geometry and magnetism,” stated Professor Young Keun Kim of Korea University, a co-corresponding author of the study. He further emphasized, “This is a rare combination of structural chirality and intrinsic ferromagnetism, enabling spin filtering at room temperature without complex magnetic circuitry or cryogenics, and provides a new way to engineer electron behavior using structural design.”
The research team successfully fabricated left- and right-handed chiral magnetic nanohelices by electrochemically controlling the metal crystallization process. A critical innovation involved introducing trace amounts of chiral organic molecules, such as cinchonine or cinchonidine, which guided the formation of helices with precisely defined handedness — a feat rarely achieved in inorganic systems. Also, the team experimentally demonstrated that when these nanohelices exhibit a right-handedness, they preferentially allow one direction of spin to pass, while the opposite spin cannot. The above marks the discovery of a 3D inorganic helical nanostructure capable of electron spin control.
“Chirality is well-understood in organic molecules, where the handedness of a structure often determines its biological or chemical function,” noted Professor Ki Tae Nam of Seoul National University, also a co-corresponding author. “But in metals and inorganic materials, controlling chirality during synthesis is extremely difficult, especially at the nanoscale. The fact that we could program the direction of inorganic helices simply by adding chiral molecules is a breakthrough in materials chemistry.”
To confirm the chirality of nanohelices, the researchers developed an electromotive force (emf)-based chirality evaluation method and measured the emf generated by the helices under rotating magnetic fields. The left- and right-handed helices produced opposite emf signals, allowing for quantitative verification of chirality even in materials that do not strongly interact with light.
The research team also found that the magnetic material itself, through its inherent magnetization (spin alignment), enables long-distance spin transport at room temperature. This effect, maintained by strong exchange energy, is constant regardless of the angle between the chiral axis and the spin injection direction, and was not observed in non-magnetic nanohelices of the same scale. The above marks the first measurement of asymmetric spin transport in a relatively macro-scaled chiral body. The team also demonstrated a solid-state device that showed chirality-dependent conduction signals, paving the way for practical spintronic applications.
Professor Kim highlighted the potential impact: “We believe this system could become a platform for chiral spintronics and architecture of chiral magnetic nanostructures.” This work represents a powerful convergence of geometry, magnetism, and spin transport, built from scalable, inorganic materials. The ability to control the handedness (left/right) and even the number of strands (double, multiple helices) using this versatile electrochemical method is expected to contribute significantly to new application areas. More

Johns Hopkins researchers have discovered new materials and a new process that could advance the ever-escalating quest to make smaller, faster and affordable microchips used across modern electronics — in everything from cellphones to cars, appliances to airplanes.
The team of scientists has discovered how to create circuits that are so small they’re invisible to the naked eye using a process that is both precise and economical for manufacturing.
The findings are published on September 11 in the journal Nature Chemical Engineering.
“Companies have their roadmaps of where they want to be in 10 to 20 years and beyond,” said Michael Tsapatsis, a Bloomberg Distinguish Professor of chemical and biomolecular engineering at Johns Hopkins University. “One hurdle has been finding a process for making smaller features in a production line where you irradiate materials quickly and with absolute precision to make the process economical.”
The advanced lasers required for imprinting on the miniscule formats already exist, Tsapatsis added, but researchers needed new materials and new processes to accommodate ever smaller microchips.
Microchips are flat pieces of silicon with imprinted circuitries that execute basic functions. During production, manufacturers coat silicon wafers with a radiation-sensitive material to create a very fine coating called a “resist.” When a beam of radiation is pointed at the resist, it sparks a chemical reaction that burns details into the wafer, drawing patterns and circuitry.
However, the higher-powered radiation beams that are needed to carve out ever-smaller details on chips do not interact strongly enough with traditional resists.

Previously, researchers from Tsapatsis’s lab and the Fairbrother Research Group at Johns Hopkins found that resists made of a new class of metal-organics can accommodate that higher-powered radiation process, called “beyond extreme ultraviolet radiation” (B-EUV), which has the potential to make details smaller than the current standard size of 10 nanometers. Metals like zinc absorb the B-EUV light and generate electrons that cause chemical transformations needed to imprint circuit patterns on an organic material called imidazole.
This research marks one of the first times scientists have been able to deposit these imidazole-based metal-organic resists from solution at silicon-wafer scale, controlling their thickness with nanometer precision. To develop the chemistry needed to coat the silicon wafer with the metal-organic materials, the team combined experiments and models from Johns Hopkins University, East China University of Science and Technology, École Polytechnique Fédérale de Lausanne, Soochow University, Brookhaven National Laboratory and Lawrence Berkeley National Laboratory. The new methodology, which they call chemical liquid deposition (CLD), can be precisely engineered and lets researchers quickly explore various combinations of metals and imidazoles.
“By playing with the two components (metal and imidazole), you can change the efficiency of absorbing the light and the chemistry of the following reactions. And that opens us up to creating new metal-organic pairings,” Tsapatsis said. “The exciting thing is there are at least 10 different metals that can be used for this chemistry, and hundreds of organics.”
The researchers have started experimenting with different combinations to create pairings specifically for B-EUV radiation, which they say will likely be used in manufacturing in the next 10 years.
“Because different wavelengths have different interactions with different elements, a metal that is a loser in one wavelength can be a winner with the other,” Tsapatsis said. “Zinc is not very good for extreme ultraviolet radiation, but it’s one of the best for the B-EUV.”
Authors include Yurun Miao, Kayley Waltz, and Xinpei Zhou from Johns Hopkins University; Liwei Zhuang, Shunyi Zheng, Yegui Zhou, and Heting Wang from East China University of Science and Technology; Mueed Ahmad and J. Anibal Boscoboinik from Brookhaven National Laboratory; Qi Liu from Soochow University; Kumar Varoon Agrawal from École Polytechnique Fédérale de Lausanne; and Oleg Kostko from Lawrence Berkeley National Laboratory. More

Unlike conventional phases of matter, the so-called non-equilibrium quantum phases are defined by their dynamical and time-evolving properties — a behavior that cannot be captured by traditional equilibrium thermodynamics. One particularly rich class of non-equilibrium states arises in Floquet systems — quantum systems that are periodically driven in time. This rhythmic driving can give rise to entirely new forms of order that cannot exist under any equilibrium conditions, revealing phenomena that are fundamentally beyond the reach of conventional phases of matter.
Using a 58 superconducting qubit quantum processor, the team from the Technical University of Munich (TUM), Princeton University, and Google Quantum AI realized a Floquet topologically ordered state, a phase that had been theoretically proposed but never before observed. They directly imaged the characteristic directed motions at the edge and developed a novel interferometric algorithm to probe the system’s underlying topological properties. This allowed them to witness the dynamical “transmutation” of exotic particles – a hallmark that has been theoretically predicted for these exotic quantum states.
Quantum computer as a laboratory
“Highly entangled non-equilibrium phases are notoriously hard to simulate with classical computers,” said the first author Melissa Will, PhD student at the Physics Department of the TUM School of Natural Sciences. “Our results show that quantum processors are not just computational devices – they are powerful experimental platforms for discovering and probing entirely new states of matter.”
This work opens the door to a new era of quantum simulation, where quantum computers become laboratories for studying the vast and largely unexplored landscape of out-of-equilibrium quantum matter. The insights gained from these studies could have far-reaching implications, from understanding fundamental physics to designing next-generation quantum technologies. More

The concept of quantum entanglement is emblematic of the gap between classical and quantum physics. Referring to a situation in which it is impossible to describe the physics of each photon separately, this key characteristic of quantum mechanics defies the classical expectation that each particle should have a reality of its own, which gravely concerned Einstein. Understanding the potential of this concept is essential for the realization of powerful new quantum technologies.
Developing such technologies will require the ability to freely generate a multi-photon quantum entangled state, and then to efficiently identify what kind of entangled state is present. However, when performing conventional quantum tomography, a method commonly used for state estimation, the number of measurements required grows exponentially with the number of photons, posing a significant data collection problem.
If available, an entangled measurement can identify the entangled state with a one-shot approach. Such a measurement for the Greenberger-Horne-Zeilinger — GHZ — entangled quantum state has been realized, but for the W state, the other representative entangled multi-photon state, it has been neither proposed nor discovered experimentally.
This motivated a team of researchers at Kyoto University and Hiroshima University to take on this challenge, ultimately succeeding in developing a new method of entangled measurement to identify the W state.
“More than 25 years after the initial proposal concerning the entangled measurement for GHZ states, we have finally obtained the entangled measurement for the W state as well, with genuine experimental demonstration for 3-photon W states,” says corresponding author Shigeki Takeuchi.
The team focused on the characteristics of the W state’s cyclic shift symmetry, and theoretically proposed a method to create an entangled measurement using a photonic quantum circuit that performs quantum Fourier transformation for the W state of any number of photons.
They created a device to demonstrate the proposed method for three photons using high-stability optical quantum circuits, which allowed the device to operate stably without active control for an extended period of time. By inserting three single photons into the device in appropriate polarization states, the team was able to demonstrate that the device can distinguish different types of three-photon W states, each corresponding to a specific non-classical correlation between the three input photons. The researchers were able to evaluate the fidelity of the entangled measurement, which is equal to the probability of obtaining the correct result for a pure W-state input.
This achievement opens the door for quantum teleportation, or the transfer of quantum information. It could also lead to new quantum communication protocols, the transfer of multi-photon quantum entangled states, and new methods for measurement-based quantum computing.
“In order to accelerate the research and development of quantum technologies, it is crucial to deepen our understanding of basic concepts to come up with innovative ideas,” says Takeuchi.
In the future, the team aims to apply their method to a larger-scale, more general multi-photon quantum entangled state, and plans to develop on-chip photonic quantum circuits for entangled measurements. More