What's that swirly pattern? It's a moiré, and it has potential power

Just as wave-like patterns can appear on a computer screen when pixels do not align, new research led by Flinders University is investigating atomic-scale "moiré patterns" in the promising field of ferroelectricity. The new study, with experts at Monash University and Nanyang Technological University in Singapore, seeks inroads into electrical and optical science by exploring these complex "superlattice" patterns in various ways to create new energy and material capabilities. "Similar to the pixel example, we can overlay single-atom thin layers in non-aligned ways to achieve physical properties not present in regular repetitive materials—including superconductivity, special insulating and conductive states, and ferroelectricity," says Dr. Pankaj Sharma, from the Institute for Nanoscale Science and Technology at Flinders University.

'Janus-faced' nanomaterials pave the way for selectively capturing radioactive pollutants

A KAIST research team has succeeded, for the first time, in synthesizing the core raw material for fabricating asymmetric MXene, a so-called "Janus-faced" nanomaterial that can perform distinct functions because of differing atomic compositions on its two sides, paving the way for the development of multifunctional materials with applications such as removing radioactive pollutants and shielding electromagnetic waves. The research team led by Professor Ho Jin Ryu from the Department of Nuclear and Quantum Engineering has successfully synthesized an asymmetric layered ceramic (a ceramic with an asymmetric structure in which atomic layers are stacked on top of each other), which is a required precursor for fabricating asymmetric MXene (a two-dimensional nanomaterial with different atomic compositions on its two sides).

A superfluid freezes and breaks the rules of physics

In a sheet of graphene, a superfluid has finally frozen—revealing a long-mysterious quantum state that blurs the line between solid and liquid.

When everyday matter is cooled, it follows a familiar path. A gas becomes a liquid, and with further cooling, that liquid turns into a solid. Quantum matter does not always follow these rules. More than a century ago, scientists discovered that helium behaves in an unexpected way at extremely low temperatures. Instead of freezing, it transforms from a normal gas into a superfluid, a rare state of matter that flows without any resistance and displays strange behaviors, including creeping up the sides of containers. Physicists have long wondered what would happen if a superfluid were cooled even further. Despite decades of effort, that question remained unanswered for nearly 50 years.

Inexpensive material compresses light, paving the way for photonic microcircuits in the terahertz range

A two-dimensional lamellar crystal composed of atomically thin layers of lead iodide (PbI2) could be used to manufacture a new generation of circuits that use light and mechanical vibrations (rather than electrons) to transmit information in the terahertz frequency range. Researchers at the Brazilian Center for Research in Energy and Materials (CNPEM), in partnership with colleagues from the University of Lille (France) and other international institutions, have studied this technology and published their findings in Nature Communications. The terahertz band corresponds to a low-energy region of the electromagnetic spectrum situated between infrared and microwaves. Despite this, it is considered crucial for developing high-speed communication technologies.

Scientists create a new form of light matter in a quasicrystal

Researchers have for the first time created a reconfigurable polariton 2D quasicrystal. The team from the Skolkovo Institute of Science and Technology (Skoltech), in collaboration with colleagues from the University of Iceland, the University of Warsaw, and the Institute of Spectroscopy of the Russian Academy of Sciences, demonstrated that this unique state of matter exhibits long-range order and a novel type of phase synchronization, opening new pathways for research into exotic phenomena such as supersolids and superfluidity in aperiodic settings. The breakthrough, published in Science Advances, was achieved using exciton-polaritons—hybrid quasiparticles that are part light and part matter. By arranging these polaritons in a Penrose tiling, a famous aperiodic pattern with five-fold symmetry, the team observed the emergence of a macroscopic coherent state where the individual nodes synchronized in a nontrivial way, unlike anything seen in conventional periodic crystals.

Monolayer WSe₂ unlocks high-performance p-type transistors that could change how future chips balance speed and power

Transistors, small devices that can amplify or switch electrical signals, are central components of all modern computer chips and digital devices. There are two main types of transistors, known as n-type and p-type transistors. N-type transistors conduct current using electrons (i.e., negatively charged particles), while p-type transistors utilize electron holes (i.e., positively charged spaces in a crystal lattice without electrons). Electronics engineers worldwide have been exploring different solutions that could help reduce the size of existing transistors without compromising their performance, which could enable the further miniaturization of electronic devices. One promising route is to fabricate transistors using two-dimensional (2D) semiconductors, semiconducting materials that are just a single atom or a few atoms thick.