Computers Math

National Institute for Materials Science, Japan. “Demonstration of spin-torque heat-assisted magnetic recording.” ScienceDaily. ScienceDaily, 21 May 2025. .
National Institute for Materials Science, Japan. (2025, May 21). Demonstration of spin-torque heat-assisted magnetic recording. ScienceDaily. Retrieved June 3, 2025 from www.sciencedaily.com/releases/2025/05/250521124447.htm
National Institute for Materials Science, Japan. “Demonstration of spin-torque heat-assisted magnetic recording.” ScienceDaily. www.sciencedaily.com/releases/2025/05/250521124447.htm (accessed June 3, 2025). More

An international research team, led by Akitoshi Shiotari of the Fritz Haber Institute of the Max Planck Society (Germany), Mariana Rossi of the Max Planck Institute for the Structure and Dynamics of Matter (Germany), and Takashi Kumagai of the Institute for Molecular Science/SOKENDAI (Japan) has successfully achieved single-molecule spectroscopic observation of hydrogen (H2) and deuterium (D2) confined within a picocavity. The picocavity was formed between a silver nanotip and a silver single-crystal substrate under cryogenic and ultrahigh vacuum conditions, using tip-enhanced Raman spectroscopy (TERS).
In recent years, light-matter interactions within atomic-scale volumes, known as picocavities, have attracted growing attention in nanoscience and nanotechnology. The extremely confined electromagnetic field generated by plasmon resonance is now regarded as a promising platform for atomic-scale measurements and quantum photonic technologies.
In this study, the smallest molecule — hydrogen — was confined within a picocavity and investigated using high-resolution TERS. This enabled picometric molecular spectroscopy to resolve its vibrational and rotational modes with unprecedented detail, revealing how the structure and vibrational properties of a single molecule are affected by the extreme spatial confinement of the picocavity. Furthermore, by precisely adjusting the gap distance between the silver tip and the silver substrate, the subtle interaction with the molecule is modified. As a result, it was discovered that only the vibrational mode of H2, and not D2, exhibited a significant change, demonstrating a pronounced isotope-dependent effect — that could not be captured by ensemble-averaged Raman or other conventional vibrational spectroscopies.
To elucidate the origin of this nontrivial isotope effect, the team conducted theoretical simulations using density functional theory (DFT), path-integral molecular dynamics (PIMD), and model Hamiltonians. These calculations revealed that the spectroscopy is exquisitely sensitive to the local interaction potential experienced by the molecules, dominated by van der Waals interactions. Quantum delocalization of the nuclei — a quantum swelling effect at low temperatures — plays a decisive role in the observed differences, favoring distinct equilibrium positions for H2 and D2 in the picocavity, which lead to a substantial difference in their vibrational spectra. Dr. Rossi says, “We were surprised at how vibrational coupling and nuclear quantum effects work hand-in-hand to cause such a large isotope effect.”
Dr. Shiotari says, “This work deepens our understanding of light-molecule interactions and the quantum dynamics of adsorbed molecules in extremely confined spaces, representing a significant step forward in precision molecular spectroscopy.” Prof. Kumagai adds, “Looking ahead, the methods and insights developed here are expected to contribute to the advanced analysis of hydrogen storage materials and catalytic reactions, as well as to the development of quantum control technologies for individual molecules — thereby supporting next-generation nanoscale sensing and quantum photonic technologies.” More

Researchers have demonstrated that by using a semiconductor with flexible bonds, the material can be moulded into various structures using nano containers, without altering its composition, the discovery could lead to the design of a variety of customised electronic devices using only a single element.
Semiconductors are vital to our daily lives, as they are found in nearly every electronic device. One of the key characteristics of semiconductors is their band gap, which determines how they conduct electric current. The band gap is typically engineered for specific applications by breaking chemical bonds or introducing additional elements into the material. However, these processes can be complex and energy-intensive.
Researchers from the University of Nottingham, the EPSRC SuperSTEM facility, Ulm University in Germany, and BNNT LLC in the USA imaged new forms of selenium using transmission electron microscopy, employing nanotubes as tiny test tubes. The study has been published today in Advanced Materials.
Dr Will Cull, research fellow in School of Chemistry, Univesity of Nottingham, who carried out the experimental work, said, ‘Selenium is an old semiconductor with a rich history, having been used in the first solar cells. In our research, we have revitalised selenium by discovering new forms that can emerge when confined to the nanoscale.’
Selenium can exist as nanowires, with its structure and bonding varying by diameter. Below a certain size, the bonding between selenium atoms changes, increasing bond angles. This causes straightening of the initially helical structure, ultimately constricting it into atomically thin wires.
Dr Will Cull said, ‘We successfully imaged new forms of selenium using transmission electron microscopy, employing nanotubes as tiny test tubes. This approach allowed us to create a new phase diagram that connects the atomic structure of selenium to the diameter of the nanowires.’
The Nottingham group previously reported using nano test tubes to image chemical reactions of individual molecules and to observe phase transitions in semiconductors. This approach enables real-time filming of chemistry at the atomic level.

Dr Will Cull said, ‘To our astonishment, we observed that the nano test tube became thinner as we imaged it! Before our very eyes, we witnessed the selenium nanowire inside the nanotube being squeezed like toothpaste, stretching and thinning. This serendipitous discovery allowed us to establish mechanisms for the transformation of one type of nanowire to another, which have implications for their electronic properties, with near-atomic precision.’
The band gap is a crucial property of semiconductors that significantly impacts their use in various devices, including solar cells, transistors, and photocatalysts. Professor Quentin Ramasse, director of EPSRC SuperSTEM, said, ‘By utilising atomically resolved scanning transmission electron microscopy coupled with electron energy loss spectroscopy, we were able to measure the band gaps of individual chains of selenium. These measurements enabled us to establish a relationship between the diameter of these nanowires and their corresponding band gaps.’
Professor Quentin Ramasse said, ‘Traditionally, carbon nanotubes have been used as nano test tubes; however, their outstanding energy absorption properties can obscure the electronic transitions of the material inside. In contrast, a newer type of nano test tube, boron nitride nanotubes, is transparent, allowing us to observe the band gap transitions in selenium nanowires contained within them.’
The famous Moore’s Law states that the number of transistors on an integrated circuit doubles approximately every two years. As a result, electronic components must become smaller. Professor Andrei Khlobystov, School of Chemistry, University of Nottingham, said, ‘We have investigated the ultimate limit for nanowire size while preserving useful electronic properties. This is possible for selenium because the phenomenon of quantum confinement can be effectively balanced by distortions in the atomic structure, thus allowing the band gap to remain within a useful range.’
The researchers hope that these new materials will be incorporated into electronic devices in the future. Accurately tuning the band gap of selenium by changing the diameter of the nanowire could lead to the design of a variety of customised electronic devices using only a single element. More

Determining how strong your drink is doesn’t need to be either guesswork or lab work. New research has made it as simple as checking your messages — and more colorful, too.
Osaka Metropolitan University researchers have developed a smartphone-compatible alcohol sensor that can visually detect a full range of ethanol concentrations, without the need for complex electronics or lab tools. Their technology allows for a broad array of potential applications in environmental monitoring, healthcare, industrial processes, and alcohol breath analysis.
Ethanol is used widely in food, pharmaceuticals, and fuel. It is also the intoxicating ingredient in many alcoholic beverages. Accurate detection of ethanol concentration, particularly in products containing both ethanol and water, is crucial for product hygiene management and quality maintenance.
“Conventional sensors typically require power sources and complex electronics, limiting their accessibility for everyday use,” said Kenji Okada, an associate professor at Osaka Metropolitan University’s Graduate School of Engineering and lead author of this study.
Seeking both selectivity and practicality, the team fabricated a portable and highly sensitive ethanol sensor built from a copper-based metal-organic framework (MOF) thin film called Cu-MOF-74.
These MOFs contain nanometer-sized pores that absorb ethanol molecules and respond with a visible color change — a phenomenon known as solvato/vapochromism. Thanks to its low light-scattering properties and high transparency, the Cu-MOF-74 film enables precise optical measurements without the need for complex lab equipment.
“Our sensor changes color in response to varying ethanol levels across the full concentration range, even at low concentrations,” Okada said.

What truly sets this technology apart is its integration with a smartphone app. Users can simply snap a photo of the film to measure ethanol concentration, making it a portable and accessible tool for use in the field, factories, or healthcare settings.
The researchers’ findings offer a smarter, simpler, and more reliable approach to alcohol sensing. From the quality of your drink to the potential future of portable breath tests, this new sensor technology brings us a colorful step closer to real-time alcohol monitoring in everyday life.
“We hope our study could open up a wide range of applications, from the food and beverage industry to environmental monitoring, industrial exhaust gas detection and alcohol breath analysis,” Okada said.
The study was published in Small Science. More

Lithium metal batteries are among the most promising candidates of the next generation of high-energy batteries. They can store at least twice as much energy per unit of volume as the lithium-ion batteries that are in widespread use today. This will mean, for example, that an electric car can travel twice as far on a single charge, or that a smartphone will not have to be recharged so often.
At present, there is still one crucial drawback with lithium metal batteries: the liquid electrolyte requires the addition of significant amounts of fluorinated solvents and fluorinated salts, which increases its environmental footprint. Without the addition of fluorine, however, lithium metal batteries would be unstable, they would stop working after very few charging cycles and be prone to short circuits as well as overheating and igniting. A research group led by Maria Lukatskaya, Professor of Electrochemical Energy Systems at ETH Zurich, has now developed a new method that dramatically reduces the amount of fluorine required in lithium metal batteries, thereby rendering them more environmentally friendly and more stable as well as cost-effective.
A stable protective layer increases battery safety and efficiency
The fluorinated compounds from electrolyte help the formation of a protective layer around the metallic lithium at the negative electrode of the battery. “This protective layer can be compared to the enamel of a tooth,” Lukatskaya explains. “It protects the metallic lithium from continuous reaction with electrolyte components.” Without it, the electrolyte would quickly get depleted during cycling, the cell would fail, and the lack of a stable layer would result in the formation of lithium metal whiskers — ‘dendrites’ — during the recharging process instead of a conformal flat layer.
Should these dendrites touch the positive electrode, this would cause a short circuit with the risk that the battery heats up so much that it ignites. The ability to control the properties of this protective layer is therefore crucial for battery performance. A stable protective layer increases battery efficiency, safety and service life.
Minimising fluorine content
“The question was how to reduce the amount of added fluorine without compromising the protective layer’s stability,” says doctoral student Nathan Hong. The group’s new method uses electrostatic attraction to achieve the desired reaction. Here, electrically charged fluorinated molecules serve as a vehicle to transport the fluorine to the protective layer. This means that only 0.1 percent by weight of fluorine is required in the liquid electrolyte, which is at least 20 times lower than in prior studies.
Optimised method makes batteries greener
The ETH Zurich research group describes the new method and its underlying principles in a paper recently published in the journal Energy & Environmental Science. An application for a patent has been made.
One of the biggest challenges was to find the right molecule to which fluorine could be attached and that would also decompose again under the right conditions once it had reached the lithium metal. As the group explains, a key advantage of this method is that it can be seamlessly integrated into the existing battery production process without generating additional costs to change the production setup. The batteries used in the lab were the size of a coin. In a next step, the researchers plan to test the method’s scalability and apply it to pouch cells as used in smartphones. More

To perform quantum computations, quantum bits (qubits) must be cooled down to temperatures in the millikelvin range (close to -273 Celsius), to slow down atomic motion and minimize noise. However, the electronics used to manage these quantum circuits generate heat, which is difficult to remove at such low temperatures. Most current technologies must therefore separate quantum circuits from their electronic components, causing noise and inefficiencies that hinder the realization of larger quantum systems beyond the lab.
Researchers in EPFL’s Laboratory of Nanoscale Electronics and Structures (LANES), led by Andras Kis, in the School of Engineering have now fabricated a device that not only operates at extremely low temperatures, but does so with efficiency comparable to current technologies at room temperature.
“We are the first to create a device that matches the conversion efficiency of current technologies, but that operates at the low magnetic fields and ultra-low temperatures required for quantum systems. This work is truly a step ahead,” says LANES PhD student Gabriele Pasquale.
The innovative device combines the excellent electrical conductivity of graphene with the semiconductor properties of indium selenide. Only a few atoms thick, it behaves as a two-dimensional object, and this novel combination of materials and structure yields its unprecedented performance. The achievement has been published in Nature Nanotechnology.
Harnessing the Nernst effect
The device exploits the Nernst effect: a complex thermoelectric phenomenon that generates an electrical voltage when a magnetic field is applied perpendicular to an object with a varying temperature. The two-dimensional nature of the lab’s device allows the efficiency of this mechanism to be controlled electrically.
The 2D structure was fabricated at the EPFL Center for MicroNanoTechnology and the LANES lab. Experiments involved using a laser as a heat source, and a specialized dilution refrigerator to reach 100 millikelvin — a temperature even colder than outer space. Converting heat to voltage at such low temperatures is usually extremely challenging, but the novel device and its harnessing of the Nernst effect make this possible, filling a critical gap in quantum technology.
“If you think of a laptop in a cold office, the laptop will still heat up as it operates, causing the temperature of the room to increase as well. In quantum computing systems, there is currently no mechanism to prevent this heat from disturbing the qubits. Our device could provide this necessary cooling,” Pasquale says.
A physicist by training, Pasquale emphasizes that this research is significant because it sheds light on thermopower conversion at low temperatures — an underexplored phenomenon until now. Given the high conversion efficiency and the use of potentially manufacturable electronic components, the LANES team also believes their device could already be integrated into existing low-temperature quantum circuits.
“These findings represent a major advancement in nanotechnology and hold promise for developing advanced cooling technologies essential for quantum computing at millikelvin temperatures,” Pasquale says. “We believe this achievement could revolutionize cooling systems for future technologies.” More

Drosophila — commonly known as fruit flies — are a valuable model for human heart pathophysiology, including cardiac aging and cardiomyopathy. However, a choke point in evaluating fruit fly hearts is the need for human intervention to measure the heart at moments of its largest expansion or its greatest contraction, measurements that allow calculations of cardiac dynamics.
Researchers at the University of Alabama at Birmingham now show a way to significantly cut the time needed for that analysis while utilizing more of the heart region, using deep learning and high-speed video microscopy for each heartbeat in the fly.
“Our machine learning method is not just fast; it minimizes human error because you don’t have to manually mark each heart wall under systolic and diastolic conditions,” said Girish Melkani, Ph.D., associate professor in the UAB Department of Pathology, Division of Molecular and Cellular Pathology. “Furthermore, you can run the analyses of several hundred hearts and look at the analyses when done for all the hearts.”
This can expand the ability to test how different environmental or genetic factors affect heart aging or pathology. Melkani envisions using deep learning-assisted studies to explore cardiac mutation models and other small animal models, such as zebrafish and mice. “Additionally, our techniques could be adapted for human heart models, providing valuable insights into cardiac health and disease. Incorporating uncertainty quantification methods could further enhance the reliability of our analyses. Moreover, the machine learning approach can predict cardiac aging with high accuracy.”
The fruit fly model has already been tremendously powerful for understanding the pathophysiological bases for several human cardiovascular diseases, Melkani says. Cardiovascular disease continues to be one of the leading causes of death and disability in the United States.
Melkani and UAB colleagues assessed their trained model on heart performance both in fruit fly cardiac aging and in a fruit fly model of dilated cardiomyopathy caused by the knockdown of a pivotal TCA cycle enzyme, oxoglutarate dehydrogenase. These automated assessments were then validated against existing experimental datasets. For example, for aging of fruit flies at one week versus five weeks of age, which is about halfway through a fruit fly’s life span, the UAB team used 54 hearts for model training and then validated their measurements against an experimental aging model with 177 hearts. Their trained model was able to reconstruct expected trends in cardiac parameters with aging.
Melkani says his team’s model can be applied to readily available consumer hardware, and his team’s code can provide calculated statistics including diastolic and systolic diameters/intervals, fractional shortening, ejection fraction, heart period/rate, and quantified heartbeat arrhythmicity.
“To our knowledge, this innovative platform for deep learning-assisted segmentation is the first of its kind to be applied to standard high-resolution high-speed optical microscopy of Drosophila hearts while also quantifying all relevant parameters,” Melkani said.
“By automating the process and providing detailed cardiac statistics, we pave the way for more accurate, efficient and comprehensive studies of heart function in Drosophila. This method holds tremendous potential — not only for understanding aging and disease in fruit flies — but also for translating these insights into human cardiovascular research.” More

A research team led by Director JO Moon-Ho of the Center for Van der Waals Quantum Solids within the Institute for Basic Science (IBS) has implemented a novel method to achieve epitaxial growth of 1D metallic materials with a width of less than 1 nm. The group applied this process to develop a new structure for 2D semiconductor logic circuits. Notably, they used the 1D metals as a gate electrode of the ultra-miniaturized transistor.
Integrated devices based on two-dimensional (2D) semiconductors, which exhibit excellent properties even at the ultimate limit of material thickness down to the atomic scale, are a major focus of basic and applied research worldwide. However, realizing such ultra-miniaturized transistor devices that can control the electron movement within a few nanometers, let alone developing the manufacturing process for these integrated circuits, has been met with significant technical challenges.
The degree of integration in semiconductor devices is determined by the width and control efficiency of the gate electrode, which controls the flow of electrons in the transistor. In conventional semiconductor fabrication processes, reducing the gate length below a few nanometers is impossible due to the limitations of lithography resolution. To solve this technical problem, the research team leveraged the fact that the mirror twin boundary (MTB) of molybdenum disulfide (MoS2), a 2D semiconductor, is a 1D metal with a width of only 0.4 nm. They used this as a gate electrode to overcome the limitations of the lithography process.
In this study, the 1D MTB metallic phase was achieved by controlling the crystal structure of the existing 2D semiconductor at the atomic level, transforming it into a 1D MTB. This represents a significant breakthrough not only for next-generation semiconductor technology but also for basic materials science, as it demonstrates the large-area synthesis of new material phases through artificial control of crystal structures.
The International Roadmap for Devices and Systems (IRDS) by the IEEE predicts semiconductor node technology to reach around 0.5 nm by 2037, with transistor gate lengths of 12 nm. The research team demonstrated that the channel width modulated by the electric field applied from the 1D MTB gate can be as small as 3.9 nm, significantly exceeding the futuristic prediction.
The 1D MTB-based transistor developed by the research team also offers advantages in circuit performance. Technologies like FinFET or Gate-All-Around, adopted for the miniaturization of silicon semiconductor devices, suffer from parasitic capacitance due to their complex device structures, leading to instability in highly integrated circuits. In contrast, the 1D MTB-based transistor can minimize parasitic capacitance due to its simple structure and extremely narrow gate width.
Director JO Moon-Ho commented, “The 1D metallic phase achieved through epitaxial growth is a new material process that can be applied to ultra-miniaturized semiconductor processes. It is expected to become a key technology for developing various low-power, high-performance electronic devices in the future.” More