Category archives: Materials

Nickel disulfide, NiS₂, is an unusual material. Its interior behaves as an electrical insulator, blocking the flow of current, while certain parts of its surface conduct electricity freely. This contradiction has puzzled physicists for decades, and a recent study offers a detailed explanation. The conduction, it turns out, is confined to tiny one-dimensional steps on […]

Researchers at Nagoya University have built a graphene nanoribbon that can switch which way it twists using a natural solvent. Graphene nanoribbons are thin ribbon-shaped structures made of fused carbon rings. Twisted or helical versions of these ribbons show promise for advanced light and electronic devices. However, no graphene nanoribbon could switch that twist on […]

Arsenic contamination in drinking water poses a critical global public health hazard. Prolonged exposure to inorganic arsenic—predominantly present in groundwater as arsenate, where arsenic exists in its +5 oxidation state—can lead to severe dermatological lesions, cardiovascular diseases, and cancers. To mitigate these health risks, the World Health Organization has established a strict provisional safety guideline […]

The kind of technology that can deliver sound to a single listener—like something out of a spy film—may soon become a reality. Researchers at Pohang University of Science and Technology (POSTECH) have developed a speaker system that can direct speech to a specific person. Light and sound behave differently. Light from a flashlight or laser […]

One of the most striking discoveries in condensed matter physics over the past few years is that simply rotating one atomically thin crystal on top of an identical layer can create entirely new electronic behavior. This idea became famous in 2018, when physicists found that graphene sheets stacked at a very particular “magic angle” could […]

Many of today’s electronic devices — from the semiconductors in your cell phone to the photovoltaic cells in your solar panels — are built on thin-film substrates. The thin film is an electronically conductive material while the substrate is an inert material. Or is it? Physicists and materials scientists have long assumed substrates do not […]

Building electronic devices often requires stacking different crystalline materials on top of one another with atomic precision. This process, called heteroepitaxy, works best when the two crystals share similar atomic patterns. When their symmetries differ, the upper crystal tends to grow in several orientations at once instead of a single one, creating defects that degrade […]

Steel and metal production are among the largest contributors to global greenhouse gas emissions, accounting for approximately 10% of global CO2 emissions. At the same time, modern technology relies on tailored steels and metals for applications in fields such as mobility, energy, infrastructure, safety and medicine. Hydrogen-based metal production offers a promising CO2-free alternative and […]

In recent years, “twistronics” has shown that simply changing how two crystal layers sit on top of each other can completely transform their electronic behavior. When two lattices are slightly mismatched in size or rotated by a small angle, they create a larger repeating interference pattern called a moiré superlattice. This long-wavelength pattern acts like […]

New research numerically demonstrates how carefully structured materials can control light in ways that are both precise and robust. It brings together ideas from photonics and topology to show how a laser can emerge from the boundary between two distinct optical regimes. The physical system considered in the study is a bilayer photonic crystal. A […]