(Funded by the National Science Foundation)
Cornell University researchers have made headway into understanding how twisted bilayer graphene becomes a superconductor. In 2023, the scientists developed a theoretical formalism to compute the highest possible superconducting transition temperature in any material obtained by stacking and twisting two-dimensional materials. For the current work, the scientists applied this theoretical formalism to twisted bilayer graphene. “One of the remarkable properties of twisted bilayer graphene is the associated tunability,” said Debanjan Chowdhury, one of the scientists involved in this study. “You have unprecedented control over temperature and the twist angle – the tiny electric fields that are applied to switch the material from being an insulator versus a superconductor – making it very easy to explore all sorts of exciting regimes in this material.”

(Funded by the National Science Foundation)
Researchers at William & Mary have measured the strength and stretchability of minuscule nanofibrils present in the silk spun by the southern house spider. The core of a spider silk strand is composed of two distinct warps that form helical loops around a central foundation fiber. The tiniest fibers, nanofibrils, are spun into a mesh that surrounds those supporting structures. The researchers found that the nanofibrils in the southern house spider’s silk could stretch 11 times their original length, more than twice the amount of any spider silk previously tested. “As amazing as spider silk as a whole is, looking at these tiny fibrils, they are even stretchier,” said Hannes Schniepp, one of the scientists involved in this study.

(Funded by the National Science Foundation)
Researchers from Northwestern University and the University of California, Los Angeles, have developed a new strategy that prevents frost formation before it begins. The researchers discovered that tweaking the texture of any surface and adding a thin layer of graphene oxide prevents frost from forming on the surface for one week, or potentially even longer. This is 1,000 times longer than current, state-of-the-art anti-frosting surfaces. As an added bonus, the new scalable surface design also is resistant to cracks, scratches, and contamination.

(Funded by the National Science Foundation)
Researchers from the University of Nebraska-Lincoln and South Dakota School of Mines and Technology are exploring the physical properties of two-dimensional materials called MXenes. Previous research by the Nebraska team on other MXene materials revealed their n-type (electron-rich) character and decreased conductivity in response to light. In contrast, the new material is the first MXene with demonstrated p-type (electron-deficient) property and increasing conductivity under illumination. “Previously studied MXenes were all n-type, but now we demonstrate the first p-type MXene,” said Alexander Sinitskii, the scientist who led this study. “This should enable complex structures where complementary MXenes are used together to achieve new electronic functionalities.”The researchers performed experiments at the Nebraska Center for Materials and Nanoscience, a user facility that is part of the National Science Foundation-funded National Nanotechnology Coordinated Infrastructure.

(Funded by the U.S. Department of Energy, U.S. Department of Defense, and the National Science Foundation)
Researchers from the University of Chicago; the University of California, Berkeley; Northwestern University; the University of Colorado Boulder; and the U.S. Department of Energy’s Argonne National Laboratory have developed a new technique for growing quantum dots – nanocrystals used in lasers, quantum light-emitting diode (QLED) televisions, and solar cells. The researchers replaced organic solvents typically used to create quantum dots with molten salt – literally superheated sodium chloride of the type sprinkled on baked potatoes. “Sodium chloride is not a liquid in your mind, but assume you heat it to such a crazy temperature that it becomes a liquid … [N]obody ever considered these liquids as media” for the synthesis of quantum dots, said Dmitri Talapin, one of the scientists involved in this study.