As is well known, the Earth behaves like a “giant magnet” (that is, it possesses a dipole magnetic field*1), and this magnetic field is thought to be generated by a dynamo process*2 driven by thermal convection of liquid iron in the Earth’s outer core. Paleomagnetism studies have shown that the Earth’s magnetic field reverses its polarity at irregular intervals, ranging from several hundred thousand to about ten million years. However, the physical mechanism responsible for these reversals remains unresolved. In particular, it is still not well understood how the polarity of the magnetic field - northward or southward - is determined.

Focusing on this polarity-determination mechanism, a research team at the National Institute for Fusion Science (NIFS) and the Graduate University for Advanced Studies, SOKENDAI, carried out a detailed study of a convective dynamo arising in a spherical-shell plasma having the same geometry as the Earth’s outer core, using three-dimensional magnetohydrodynamic simulations*3. As a result, they showed for the first time that, in an Earth-like dynamo, the polarity of the magnetic field (northward or southward) is determined randomly, not by the direction of convection, but by extremely weak magnetic perturbations present initially. Moreover, depending on subtle differences in the imposed magnetic perturbations, the system settles into either a northward - or southward- polarity state and remains there (bi-stability of the dipole polarity). Thus, the polarity of the Earth’s magnetic field may likewise have been determined by tiny fluctuations present when the geodynamo first emerged some four billion years ago. That polarity would then be expected to persist, yet in reality the geomagnetic field undergoes repeated reversals. This suggests that geomagnetic reversals may be caused by physical effects not included in the present computational model.

Endowing and controlling topologically structured emission in microlasers is highly desired yet remains challenging. Toward this goal, researchers at Fudan University developed a compound topological microcavity design for vectorial lasing with designable topological charges. Leveraging quasi-BIC Möbius-like correspondence, they establish a direct, predictive link between cavity morphology and topological charge of emitted lasing profile. Experimentally, they demonstrate vectorial lasing with topological charges from −5 to +5, representing a substantial advance toward compact topological light sources.

Researchers have developed an ultra-thin optical film that improves the quality of the light used in LCD resin-based 3D printerswhich could make it possible to 3D-print medical-grade or industrial-grade products at a lower cost.

Metal-organic frameworks, better known as MOFs, are among the most intensely studied materials for addressing major environmental challenges. Their highly ordered, ultra‑porous architecture enables applications ranging from CO₂ capture and air or water purification to catalysis and hydrogen production. It is therefore no surprise that MOFs have drawn global attention in recent years, notably with their recognition by the 2025 Nobel Prize in Chemistry, as they play an increasingly central role in the development of sustainable technologies. 

Despite their promise, MOFs remain challenging to synthesize with high precision. Conventional solvotherma methods typically;require high temperatures (up to 200 °C) and long reaction times, making them energy‑intensive and difficul to control. These harsh conditions can compromise structural precision and limit functiona performance.

This constraint has now been overcome by Professor Dongling Ma, a nanomaterials expert at the Institut national de la recherche scientifique (INRS) and Canada Research Chair in Advanced Functional Nanocomposites. In collaboration with researchers from McGill University, her team has developed a photochemical synthesis strategy that enables MOFs to be formed under mild, ambient conditions.