Using new techniques, Yale researchers have demonstrated the ability to use lasers to cool quantized vibrations of sound within massive objects to their quantum ground state, the lowest energy allowable by quantum mechanics. This breakthrough could benefit communications, quantum computing, and other applications. The results are published in Nature Physics.
Scientists have turned a longstanding challenge in electronics—material defects—into a quantum-enhanced solution, paving the way for new-generation ultra-low-power spintronic devices. Spintronics, short for “spin electronics,” is a field of technology that aims to go beyond the limits of conventional electronics.
Traditional devices rely only on the electric charge of electrons to store and process information. Spintronics takes advantage of two additional quantum properties: spin angular momentum, which can be imagined as a built-in “up” or “down” orientation of the electron, and orbital angular momentum, which describes how electrons move around atomic nuclei.
By using these extra degrees of freedom, spintronic devices can store more data in smaller spaces, operate faster, consume less energy, and retain information even when the power is switched off.
To demonstrate practical functionality, the team incorporated various achiral luminescent dyes (red, green, blue) into the co-assembled polymer framework. The dyes were anchored via hydrogen bonding and adopted the chirality of their environment during co-assembly, resulting in CPL in all three colors.
Notably, this full-color CPL capability is rare, with red emission being especially difficult to achieve. In this system, the polymer matrix enabled chirality transfer and also passivated the dye molecules, leading to brighter, longer-lasting light with higher quantum yields compared to the same dyes used alone.
“The ability to produce strong CPL across the visible spectrum broadens the scope for practical applications, particularly in photonic devices that require low optical losses and high signal discrimination,” added Prof Lin.
A fading sense of smell can be one of the earliest signs of Alzheimer’s disease even before cognitive impairments manifest. Research by scientists at DZNE and Ludwig-Maximilians-Universität München (LMU) sheds new light on this phenomenon, pointing to a significant role for the brain’s immune response, which seems to fatally attack neuronal fibers crucial for the perception of odors.
The study, published in Nature Communications, is based on observations in mice and humans, including analysis of brain tissue and so-called PET scanning. These findings may help to devise ways for early diagnosis and, consequently, early treatment.
The researchers came to the conclusion that these olfactory dysfunctions arise because immune cells of the brain called “microglia” remove connections between two brain regions, namely the olfactory bulb and the locus coeruleus.
Features of spaceflight such as gravitational changes and circadian rhythm disruption—not to mention radiation—take a toll on the body, including muscle wasting and decreased bone density. These may even affect the ability to produce healthy offspring.
Studying the impact of spaceflight on germ cells —egg and sperm precursor cells—is particularly important because they directly influence the next generation, and any irreversible damage done to these will likely be transmitted to offspring. Previous examinations of embryonic stem cells that have undergone spaceflight have revealed abnormalities, but the exact cause of the damage has remained unknown.
This inspired a team of researchers at Kyoto University to test the potential damage to spermatogonial stem cells during spaceflight and the resulting offspring. The team utilized stem cells from mice, which have a much shorter reproductive life span than humans.
For the first time, researchers at Umeå University have demonstrated the full capabilities of their large-scale laser facility. In a study published in Nature Photonics, the team reports generating a combination of ultrashort laser pulses, extreme peak power, and precisely controlled waveforms that make it possible to explore the fastest processes in nature.
