Letters

The tunnelling electroresistance effect that occurs at ferroelectric tunnel junctions could form the basis for a class of potential memory applications. Now, an enhanced effect is observed in a complex oxide interface as a result of a ferroelectrically induced phase transition.

The fabrication of microchips with vertically stacked circuits is challenging because they require arrays of electrical interconnections between the circuits, where accessibility is limited. An approach to generate conductive, mechanically stable plug-and-socket interconnections through three-dimensional actin-filament self-organization and selective metallization offers a potential solution to this problem.

The control and manipulation of domain walls in perpendicularly magnetized nanowires by means of an electric current has gained attention for possible device applications. Now, the depinning of domain walls in Pt/Co/Pt nanowires is shown to be driven by the spin Hall effect.

The crystallization of many minerals from solution has been shown to involve disordered precursors that agglomerate into an amorphous intermediate phase, a pathway that seems to contradict classical nucleation theory. It is now found that the crystallization of magnetite—a magnetic iron oxide with many bio- and nanotechnological applications—occurs classically from the accretion of precursors in the absence of amorphous intermediates.

How the shape of jammed particle packings influences their mechanical response is unknown except for specific cases. An algorithm that mutates the shapes of packings of bonded identical spheres to optimize the packing’s mechanical performance, and the experimental testing of the optimized shapes through three-dimensional printing, are now reported.

Metallic and ceramic surfaces can be rendered hydrophobic through a combination of multiscale surface structures and polymeric modifiers, but the imparted hydrophobicity is not robust to harsh environments. It is now shown that the lanthanide oxide series—a class of ceramics—is intrinsically hydrophobic as a result of their unique electronic structure, even after exposure to high temperatures and abrasive wear.

The expansion of a material in one or more directions under increasing hydrostatic pressure is a phenomenon known as negative linear compressibility. The demonstration that zinc dicyanoaurate exhibits an unusually large negative linear compressibility opens up possibilities for designing other materials with comparable properties.

It is shown that by controlling the relaxation of graphene adhered on a biaxially pre-stretched polymer substrate, graphene films can be reversibly crumpled and unfolded to form tailored hierarchical structures with tunable wettability and transmittance, and that the crumpled graphene–polymer laminates can be used as actuators.

A suitably engineered plasmonic metamaterial featuring topologically protected sharp phase variations close to a zero-reflection point of incident lightwaves has now been demonstrated. Exploiting the high sensitivity of the abrupt phase changes, and by using reversible hydrogenation of graphene and binding of streptavidin–biotin, the detection of individual biomolecules and an areal mass sensitivity of the order of fg mm⁻² is reported.

The design of open crystalline arrangements of colloidal particles with attractive patches has been hampered by the difficulty in exploring the full range of conceivable parameters both experimentally or with simulations. An analytical theory that explains the role of entropy in stabilizing open colloidal lattices and that predicts the conditions at which stable crystal structures of patchy particles form is now reported.

Because it is an intrinsically slow technique, scanning tunnelling microscopy is not usually useful for studying the dynamics of particles on a surface. This issue is now solved by using scanning noise microscopy, which yields a complete characterization of copper phthalocyanine molecules on Cu(111), ranging from the dynamical processes to the underlying electronic structure at the single-molecule level.

Emulating the spiking phenomena associated with neural activity in technological devices offers the promise of drastically improving their efficiency and scale. The fabrication of a neuristor that consists of nanoscale Mott memristors provides a step towards making such devices practical for integrated circuit applications.

The standard picture of organic photovoltaics predicts that excitons, which are created under light irradiation, thermalize before dissociation into free electrons and holes. Experimental results and calculations on a low-bandgap polymer–fullerene blend now illustrate the dynamics of hot charge-transfer states and their contribution to charge generation in bulk heterojunctions.

Solid-state spin qubits offer promise as building blocks for quantum computers. Now, efficient quantum control is demonstrated over hybrid nuclear–electronic qubits in bismuth-doped silicon, as a consequence of the strong hyperfine interactions in this system.

Rechargeable metal–air batteries are considered particularly attractive due to their potential high-energy densities and simplicity of the underlying cell reaction. A room-temperature sodium–oxygen cell with an ether-based electrolyte demonstrates enhanced current densities using pure carbon cathodes without an added catalyst.

The dynamical properties of single-chain magnets are difficult to control experimentally. The demonstration of a scheme for switching individual spins optically now allows for the study and manipulation of dynamical processes in magnetic nanowires with comparative ease.

The appealing electronic properties of the monolayer semiconductor molybdenum disulphide make it a candidate material for electronic devices. The observation of tightly bound trions in this system—which have no analogue in conventional semiconductors—opens up possibilities for controlling these quasiparticles in future optoelectronic applications.

A critical component for chip-scale integrated photonics would be a non-reciprocal optical waveguide allowing light to travel in only one direction while reflecting it in the opposite one. Inspired by concepts of parity-time-symmetric quantum theories, a periodically modulated dielectric waveguide displaying unidirectional reflection is now demonstrated, reflecting light at telecom frequencies in only one direction.

Determining crystal structures from diffraction experiments can be labour intensive and prone to errors. A hybrid approach combining experimental diffraction data, statistical symmetry information and first principles-based algorithmic optimization is now proposed to automatically solve crystal structures.

The exterior surface of cell membranes in eukaryotes is surrounded by glycans. It is now found that the spatial configuration of these polysaccharide molecules controls the phase behaviour of multiphase lipid membranes—either by stabilizing ordered lipid domains or by suppressing macroscopic lipid phase separation—and that this glycan-induced patterning is thermally reversible.