Pines' demon observed as a 3D acoustic plasmon in SrRuO.

The characteristic excitation of a metal is its plasmon, which is a quantized collective oscillation of its electron density. In 1956, David Pines predicted that a distinct type of plasmon, dubbed a 'demon', could exist in three-dimensional (3D) metals containing more than one species of charge carrier. Consisting of out-of-phase movement of electrons in different bands, demons are acoustic, electrically neutral and do not couple to light, so have never been detected in an equilibrium, 3D metal.

Synthesis of an aqueous, air-stable, superconducting 1T'-WS monolayer ink.

Liquid-phase chemical exfoliation can achieve industry-scale production of two-dimensional (2D) materials for a wide range of applications. However, many 2D materials with potential applications in quantum technologies often fail to leave the laboratory setting because of their air sensitivity and depreciation of physical performance after chemical processing. We report a simple chemical exfoliation method to create a stable, aqueous, surfactant-free, superconducting ink containing phase-pure 1T'-WS monolayers that are isostructural to the air-sensitive topological insulator 1T'-WTe.

Simultaneous Imaging of Dopants and Free Charge Carriers by Monochromated EELS.

Doping inhomogeneities in solids are not uncommon, but their microscopic observation and understanding are limited due to the lack of bulk-sensitive experimental techniques with high enough spatial and spectral resolution. Here, we demonstrate nanoscale imaging of both dopants and free charge carriers in La-doped BaSnO (BLSO) using high-resolution electron energy-loss spectroscopy (EELS). By analyzing high- and low-energy excitations in EELS, we reveal chemical and electronic inhomogeneities within a single BLSO nanocrystal.

Understanding the crystallographic and nanomechanical properties of bryozoans.

This study examines how microscale differences in skeletal ultrastructure affect the crystallographic and nanomechanical properties of two related bryozoan species: (i) Hornera currieae, which is found at relatively quiescent depths of c. 1000 m, and (ii) Hornera robusta, which lives at depths of 50-400 m where it is exposed to currents and storm waves. Microstructural and Electron Backscatter Diffraction (EBSD) observations show that in both species the secondary walls are composed of low-Mg calcite crystallites that grow with their c-axes perpendicular to the wall.

Hierarchically Ordered Nanoporous Carbon with Exclusively Surface-Anchored Cobalt as Efficient Electrocatalyst.

A hierarchically ordered porous carbon electrocatalyst with exclusively surface-anchored cobalt species, dubbed Co@HOPC, is synthesized from polyaniline and cobalt-functionalized silica microparticles templates, and its high electrocatalytic activity for the oxygen evolution reaction (OER) is demonstrated. The material requires a small potential (320 mV) to drive the reaction with a current density of 10 mA cm and a small Tafel slope of 31.2 mV dec .