RIKEN physicists have discovered for the first time why the magnitude of the electron flow depends on direction in a special kind of magnet. This finding could help to realize future low-energy devices.
The work is published in the journal Science Advances.
In a normal magnet, all the spins of electrons point in the same direction. In a special class of magnets known as chiral magnets, the electron spins resemble a spiral staircase, having a helical organization.
Scientists from the University of Cambridge have developed a new reactor that converts natural gas (a common energy source primarily composed of methane) into two highly valuable resources: clean hydrogen fuel and carbon nanotubes, which are ultralight and much stronger than steel.
Hydrogen is a promising green fuel because it burns completely, producing only water vapor and zero carbon dioxide. However, the way we make hydrogen today typically involves using high-pressure steam to break apart gas molecules, which releases significant amounts of CO2 as a byproduct.
To avoid this, the Cambridge team wanted to perfect a technique called methane pyrolysis, which converts methane into hydrogen and solid carbon without producing carbon dioxide. However, until now, no one has been able to perform this process efficiently enough for large-scale use because traditional reactors waste too much gas.
Prof. An Tao from the Shanghai Astronomical Observatory (SHAO) of the Chinese Academy of Sciences has proposed a novel “precessing magnetic jet engine” model to explain the peculiar gamma-ray burst (GRB) 250702B, a rare cosmic explosion discovered on July 2, 2025.
This GRB exhibited periodic flares approximately every 47 minutes over more than three hours. The new model elucidates the physical origin of this “heartbeat” and resolves the mysteries surrounding its extremely hard spectrum and apparent excess energy. Results were published in The Astrophysical Journal Letters on December 2.
GRB 250702B was detected by high-energy observatories, including the Fermi satellite and Konus-Wind. Its uniqueness lies in its temporal structure. The entire burst lasted approximately 3.2 hours and included three distinct, intense gamma-ray pulses with intervals that were integer multiples of a base period of about 2,825 seconds. Interestingly, approximately one day prior to this event, China’s “Einstein Probe” satellite detected a softer X-ray burst at the same location, acting as a precursor to the main event. This combination of “early warm-up plus hour-scale heartbeat” is extremely rare in GRB observations.
In Nature Communications, a research team affiliated with UNIST present a fully biodegradable, robust, and energy-efficient artificial synapse that holds great promise for sustainable neuromorphic technologies. Made entirely from eco-friendly materials sourced from nature—such as shells, beans, and plant fibers—this innovation could help address the growing problems of electronic waste and high energy use.
Traditional artificial synapses often struggle with high power consumption and limited lifespan. Led by Professor Hyunhyub Ko from the School of Energy and Chemical Engineering, the team aimed to address these issues by designing a device that mimics the brain’s synapses while being environmentally friendly.
Metal nanostructures can concentrate light so strongly that they can trigger chemical reactions. The key players in this process are plasmons—collective oscillations of free electrons in the metal that confine energy to extremely small volumes. A new study published in Science Advances now shows how crucial adsorbed molecules are in determining how quickly these plasmons lose their energy.
The team led by LMU nanophysicists Dr. Andrei Stefancu and Prof. Emiliano Cortés identified two fundamentally different mechanisms of so-called chemical interface damping (CID), the plasmon damping caused by adsorbed molecules. Which mechanism dominates depends on how the electronic states of the molecule align with those of the metal surface, gold in this case—and this alignment is even reflected in the material’s electrical resistance.
