Research articles

A promising strategy for achieving information storage devices with low energy consumption is to avoid using applied magnetic fields as a means to manipulate the magnetization of materials. Now, the class of materials that can be switched by all-optical means is shown to extend beyond alloys consisting of rare earths and transition metals.

Glioblastoma multiforme—an aggressive form of brain tumour —is known to migrate along white matter tracts and blood vessels. Now, aligned polycaprolactone nanofibres within a polymeric carrier are shown to guide tumour cells from the primary tumour site to an extracortical hydrogel ‘sink’ and hence lower tumour volume in the brain.

Cavity polaritons have been extensively studied in inorganic materials. An organic polariton condensate is now demonstrated to occur in the strongly interacting regime, at room temperature, in a cavity containing an organic polymer.

Spin currents form the basis of spintronics as a viable approach for future memory and information storage devices. Now, it is shown that a thermal spin current can be induced and controlled by applying a voltage.

Remarkably stable excitations known as skyrmions have recently garnered significant attention in condensed-matter systems. It is now shown that skyrmions in thin films of MnSi and Cu₂OSeO₃ can be made to rotate as a result of thermal fluctuations.

Electric-field-induced switching of material’s magnetization is a promising approach for achieving energy-efficient memory devices. By taking advantage of the strong magnetoelectric coupling with a BaTiO₃ substrate, a small electric field is used to switch a FeRh thin film from anti- to ferromagnetic above room temperature.

Magnetic memory devices are typically based on ferromagnetic materials. Now, a memory resistor based on the antiferromagnetic alloy FeRh is demonstrated at room temperature.

High-resolution atomic force microscopy coupled with a frequency modulation method is used to visualize flexible, monoclonal immunoglobulin G (IgG) antibodies and their interactions with antigens in aqueous solutions. IgG molecules, which individually have Y-shaped structures, self-assemble into hexamers that form crystalline two-dimensional arrangements on a mica substrate, and are observed to retain their immunoactivity within the crystal.

Spermine—a polyamine found in eukaryotic cells—mediates the assembly of taxol-stabilized microtubules into hexagonally packed bundles. It is now shown with electron microscopy and small-angle X-ray scattering that at higher concentrations of spermine the bundles disassemble and then reassemble into inverted tubulin tubules that expose the inner surface of the precursor microtubules, and that this results from spermine triggering a straight-to-curved conformation transition in the taxol-stabilized tubulin oligomers.

Resolving the internal structure of water molecules adsorbed on solid surfaces is challenging. Submolecular-resolution imaging of individual water monomers and tetramers on NaCl(001) films supported by a Au(111) substrate is now reported. The molecular orbitals of adsorbed water were directly visualized, which lead to the discrimination between the orientation of the monomers and the tetramers H-bond directionality.

Colloidal particles dispersed in liquid crystals induce nematic fields and topological defects that are dictated by the topology of the colloidal particles. However, little is known about such interplay of topologies. It is now shown that knot-shaped microparticles in liquid crystals induce defect lines that get entangled with the colloidal knots, and that such mutually tangled configurations satisfy topological constraints and follow predictions from knot theory.