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Laser frequency combs are light sources that produce evenly spaced, sharp lines across the spectrum, resembling the teeth of a comb. They serve as precise rulers for measuring time and frequency, and have become essential tools in applications such as lidar, high-speed optical communications, and space navigation. Traditional frequency combs rely on large, lab-based lasers. However, recent advancements have led to the development of chip-scale soliton microcombs, which generate ultrashort pulses of light within microresonators.

One of the key challenges for soliton microcombs is jitter, which refers to tiny fluctuations in the timing of their light pulses. These fluctuations, caused by or internal instabilities, can degrade the precision and reliability of systems that rely on exact timing. For example, in lidar, jitter can cause uncertainty in distance measurements, and in high-speed data transmission, it can introduce signal distortion and reduce data integrity.

As reported in Advanced Photonics Nexus, an international research team has addressed this problem by developing a new platform based on dispersion-managed (DM) silicon nitride (Si3N4) microresonators operating at an 89 GHz repetition rate.

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Batteries are becoming more and more powerful. A discovery by researchers at the Max Planck Institute for Medical Research in Heidelberg could now give them a significant energy boost.

A team led by Max Planck Director Joachim Spatz has discovered that metal fleeces used as contact material in significantly accelerate the charge transport of metal ions, in particular. This makes it possible to build significantly thicker electrodes than is standard today. It means that roughly half of the contact metal and other materials that do not contribute to can be saved, and makes it possible for researchers to significantly increase the energy density in batteries.

The findings are published in the journal ACS Nano.

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In conventional heat-assisted magnetic recording (HAMR), a laser is used to locally heat the recording medium to facilitate data writing. However, the thermal energy applied is largely dissipated within the medium and does not contribute directly to the recording efficiency. Moreover, this high-temperature process consumes substantial energy and raises concerns regarding the magnetic and physical degradation of the medium, especially under repeated use.

The research team focused on the temperature gradient generated within the recording medium during laser irradiation. They developed a novel structure by inserting an antiferromagnetic manganese-platinum (MnPt) layer beneath the iron-platinum (FePt) recording layer. This structure achieved approximately 35% improvement in recording efficiency compared to conventional HAMR.

This enhancement stems from generated by the , which induce spin torque that assists magnetic switching—effectively augmenting the conventional thermal assist effect. Furthermore, the study demonstrated that spin torque can be applied to (HDDs), paving the way for a new class of recording technologies.

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With the declared aim of measuring matter under extreme pressure, an international research collaboration headed by the University of Rostock and the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) used the high-performance laser DIPOLE 100-X at the European XFEL for the first time in 2023. With spectacular results: In this initial experiment they managed to study liquid carbon—an unprecedented achievement as the researchers report in the journal Nature.

Liquid carbon can be found, for example, in the interior of planets and plays an important role in like nuclear fusion. To date, however, only very little was known about carbon in its because in this state it was practically impossible to study in the lab: Under normal pressure, carbon does not melt but immediately changes into a gaseous state.

Only under and at temperatures of approximately 4,500 degrees Celsius—the highest melting point of any material—does carbon become liquid. No container would withstand that.

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A broad systematic review has revealed that quantum computing applications in health care remain more theoretical than practical, despite growing excitement in the field.

The comprehensive study published in npj Digital Medicine, which analyzed 4,915 research papers published between 2015 and 2024, found little evidence that quantum machine learning (QML) algorithms currently offer any meaningful advantage over classical computing methods for health care applications.

“Despite in research claiming quantum benefits for health care, our analysis shows no consistent evidence that quantum algorithms outperform classical methods for clinical decision-making or health service delivery,” said Dr. Riddhi Gupta from the School of Mathematics and Physics and the Queensland Digital Health Center (QDHeC) at the University of Queensland.

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Ferromagnetic semiconductors (FMSs) combine the unique properties of semiconductors and magnetism, making them ideal candidates for developing spintronic devices that integrate both semiconductor and magnetic functionalities. However, one of the key challenges in FMSs has been achieving high Curie temperatures (TC) that enable their stable operation at room temperature.

Though previous studies achieved a TC of 420 K, which is higher than room temperature, it was insufficient for effectively operating the spin , highlighting the demand for an increase in TC among FMSs. This challenge has been featured among the 125 unsolved questions selected by the journal Science in 2005.

Materials such as (Ga, Mn)As exhibit low TC, limiting their practical use in spintronic devices. While adding Fe to narrow bandgap semiconductors like GaSb seemed promising, incorporating high concentrations of Fe while maintaining crystallinity proved difficult, restricting the attainable TC.

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A new camera setup can record three-dimensional movies with a single pixel. Moreover, the technique can obtain images outside the visible spectrum and even through tissues. The Kobe University development thus opens the door to holographic video microscopy.

Holograms are not only used as fun-to-look-at safety stickers on , or banknotes; they have scientific applications in sensors and in microscopy as well. Traditionally, holograms require a laser for recording, but more recently, techniques that can record holograms with or light emanating from a sample have been developed.

There are two main techniques that can achieve this: one is called “FINCH” and uses a 2D image sensor that is fast enough to record movies, but is limited to visible light and an unobstructed view, while the other is called “OSH,” which uses a one-pixel sensor and can record through scattering media and with light outside the visual spectrum, but can only practically record images of motionless objects.

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Researchers have detailed the physics behind a phenomenon that allows them to create spin in liquid droplets using ultrasound waves, which concentrates solid particles suspended in the liquid. The discovery will allow researchers to engineer technologies that make use of the technique to develop applications in fields such as biomedical testing and drug development.

“By creating on the surface of a piezoelectric substrate, we can induce spin in a liquid droplet that is resting on that substrate,” explains Chuyi Chen, an assistant professor of mechanical and at North Carolina State University and co-lead author of a paper on the work published in Science Advances.

The oscillation of the ultrasound waves pushes the fluid inside the droplet to stream in a circle, but the surface tension of the droplet prevents the droplet from spreading out into a flat sheet. A combination of forces from the ultrasound waves, the spinning droplet, and the fluid moving within the droplet drives particles inside the droplet to move in a helical pattern, essentially corkscrewing through the droplet to come together at a central point.

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A recent study has mathematically clarified how the presence of crystals and gas bubbles in magma affects the propagation of seismic P-waves. The researchers derived a new equation that characterizes the travel of these waves through magma, revealing how the relative proportions of crystals and bubbles influence wave velocity and waveform properties.

The ratio of crystals to bubbles in subterranean magma reservoirs is crucial for forecasting . Due to the inaccessibility of direct observations, scientists analyze seismic P-waves recorded at the surface to infer these internal characteristics.

Previous studies have predominantly focused on the influence of , with limited consideration given to crystal content. Moreover, conventional models have primarily addressed variations in wave velocity and amplitude decay, without capturing detailed waveform transformations.

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Computer scientists at ETH Zurich have uncovered a serious flaw in Intel processors that could let attackers steal sensitive information by exploiting how modern chips predict upcoming actions. Using specially designed sequences of instructions, hackers can bypass security boundaries and gradually read the entire memory of a shared processor. This vulnerability affects a wide range of Intel chips used in personal computers, laptops, and cloud servers.

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