Articles in 2011

Active shortening in the Central Andes shifted from the western to the eastern margin between 10-7 Myr ago, but the mechanism of formation is still unclear. Here, using critical wedge theory and local-scale fault friction calculations, this shift is proposed to have been controlled by changes in erosion patterns.

The unique band structure of topological insulators gives rise to insulating bulk and unusual metallic surface properties. By tuning the content of Sb in the ternary compound (Bi_1–xSb_x)₂Te₃, Wang and collaborators show it is possible to control the precise features of the band structure in a continuous fashion.

Unlike the other iron-based superconductors, the parent compounds of the alkaline iron selenide superconductors are insulators. Dai and colleagues examine the spin-wave excitations in these materials and uncover evidence for a common magnetic origin for all iron-based superconductors.

Magnetic resonance force microscopy is a scanning probe technique capable of detecting and imaging electron spins. Vinanteet al.bring the operating temperature of this method into the millikelvin temperature regime, revealing spin diffusion phenomena that were hitherto inaccessible.

Nanomechanical resonators are attractive as ultra-low concentration sensors of biomolecules, as their small scale allows for sensitive mass detection. Here, using a nanowire array as part of a photonic crystal, such a device is presented for light trapping, absorption and low-concentration sensing.

The night sky viewed from Earth is very bright at infrared wavelengths due to atmospheric emission, making land-based astronomy difficult in this spectral region. Here, a photonic filter is demonstrated to suppress this unwanted light, opening new paths to infrared astronomy with current and future telescopes.

Herpesvirus glycoprotein D binds to nectin 1 and the herpes virus entry mediator protein on the surface of host cells. In this study, Zhanget al. report the crystal structure of glycoprotein D in complex with the immunoglobulin-like domains of nectin 1, which suggests that binding of glycoprotein D to nectin 1 prevents nectin 1 dimerization.

Quantum objects are subject to decoherence effects due to the surrounding environment. This study demonstrates experimentally a counterintuitive example of anomalous decoherence, in which electron spins residing at nitrogen vacancy centres in diamond display longer coherence times under stronger noises.

Chiral liquid crystals of two-dimensional colloids have not been extensively investigated. Xu and Gao show that graphene oxide can form chiral liquid crystals, and demonstrate that they can be spun into macroscopic fibres, and that subsequent chemical reduction provides graphene fibres with high conductivity.

Activin is known to have a role in wound healing, but its role in skin cancer is unknown. Antsiferovaet al. show that activin is elevated in human skin tumours, and by modulating epidermal immune cells, exacerbates tumour progression in a mouse model of skin cancer.

Among the wide range of potential applications of graphene, photodetection is believed to be among the most promising. By combining graphene with plasmonic nanostructures, Duan and colleagues observe dramatic improvements in the efficiency and spectral sensitivity of graphene-based photodetectors.

Reinforcement learning quantifies the change in behaviour in response to past experience. Using field goal attempt data from basketball, Neiman and Loewenstein demonstrate that even one failed or made attempt has an impact on subsequent attempts, showing that players overgeneralize from their most recent actions.

Populations of the same species living in different habitats can differ in sensory traits driving speciation, but it is not known if this variation limits gene flow. Here, a genetic and acoustic study of the bumblebee bat suggests that geographic distance, instead of echolocation divergence, limits gene flow.

Topological insulators are a unique class of materials characterized by exotic metallic states at their surface, while remaining insulated in the bulk. Sacépéet al. show how to manipulate normal and superconducting electronic transport at the surface of the topological insulator Bi₂Se₃, by tuning a gate-voltage to vary the electronic density.

Human children use referential gestures such as showing, offering and pointing, which are thought to form the foundation of language skills. Here, evidence is provided of ravens (Corvus corax) using showing and offering to direct other's attention, as an example of referential gesturing in a non-primate lineage.

X-ray ptychography has been used to extend the field of view in high-resolution quantitative imaging. Godardet al. develop Bragg-mode ptychography to reconstruct, in three dimensions, a crystalline specimen that is too large to be studied as a single object with a coherence-limited X-ray beam.

The propagation of magnetic domain walls in nanowires offers promise as the basis of future memory storage technologies. Muñoz and Prieto show that the random pinning of domain walls to structural defects in the nanowires can be suppressed at low fields, thus improving the reliability of the transmission of the domain walls substantially.

The controllable modification of graphene by chemical functionalization can modulate its optical and electronic properties. Sunet al. devise a functionalisation-based method to pattern graphane/graphene superlattices within a single sheet of graphene.

Dissociation of ice into an ionic solid is rare due to the high energy cost of proton transfer. In this study, structure search simulation is used to predict the formation of a partially ionic phase in ice at low temperature and high pressure, which consists of coupled alternate layers of hydroxide and hydronium.

As quantum information processing continues to develop apace, the need for integrated photonic devices becomes ever greater for both fundamental measurements and technological applications. To this end, Crespiet al.demonstrate a high-fidelity photonic controlled-NOT gate on a glass chip.