The properties of semiconductor quantum dots can now be controlled down to the level of single electrons and spins. These solid-state 'artificial atoms' have inspired scientists to look at them as possible building blocks for realizations of quantum computers, with unexpected consequences.

Authors: Hugo Ribeiro & Guido Burkard

Semiconducting quantum dots have been extensively investigated with the idea of using single spins for quantum computing. Whereas access to single electrons and their spins has become routine, the challenges posed by nuclear spins remain ever present.

Author: K. F. Kelton

Discrepancies in the glass-forming ability of metallic glasses have been explained in terms of the presence of local structural features in the liquid. Findings from molecular dynamics simulations now show that the structure of the crystal/liquid interface may play a bigger role than previously thought.

Authors: Oscar J. Abilez & Joseph C. Wu

Technologies to isolate colonies of human pluripotent stem cells from other cell types in a high-throughput manner are lacking. A microfluidic-based approach that exploits differences in the adhesion strength between these cells and a substrate may soon fill the gap.

Author: Jordan D. Miller

The application of imaging techniques prevalent in materials science to the biological process of soft tissue calcification lends new insight into age-related cardiovascular disease.

Authors: Naside Gozde Durmus, Savas Tasoglu & Utkan Demirci

Tissue-mimicking printed networks of droplets separated by lipid bilayers that can be functionalized with membrane proteins are able to spontaneously fold and transmit electrical currents along predefined paths.

Author: Joaquin Fernández Rossier

A series of breakthroughs is making the fabrication of single-atom devices possible. Their behaviour is controlled by the quantum state of single dopants, and they hold promise for applications such as quantum bits, magnetometers and memories.

Author: Richard J. Warburton

Authors: E. A. Chekhovich, M. N. Makhonin, A. I. Tartakovskii, A. Yacoby, H. Bluhm, K. C. Nowack & L. M. K. Vandersypen

Authors: Chunguang Tang & Peter Harrowell

Our ability to exploit the benefits of metallic glasses depends on identifying alloys of high glass-forming ability (GFA). So far, the established empirical correlations of GFA (ref. ) are statistical guides at best and lack a microscopic rationale. Although simulations have the potential to provide this physical insight into the maximum crystallization rate, crystal nucleation is often too slow to be observed. In contrast, measuring the growth rate of a planar crystal surface represents an accessible route to understanding ordering kinetics. Here we use molecular dynamics simulations to show that the crystal growth rate for an important binary glass former, CuZr, is significantly slower than that of a poor glass former, NiAl. In accounting for this difference, we find that the crystal/liquid interface in NiAl exhibits a significantly greater width than that of CuZr. Our results suggest that the crystal/liquid interfacial structure exerts an important influence on the GFA of alloys.

Authors: S. Ishiwata, Y. Shiomi, J. S. Lee, M. S. Bahramy, T. Suzuki, M. Uchida, R. Arita, Y. Taguchi & Y. Tokura

The electron mobility is one of the key parameters that characterize the charge-carrier transport properties of materials, as exemplified by the quantum Hall effect as well as high-efficiency thermoelectric and solar energy conversions. For thermoelectric applications, introduction of chemical disorder is an important strategy for reducing the phonon-mediated thermal conduction, but is usually accompanied by mobility degradation. Here, we show a multilayered semimetal β-CuAgSe overcoming such a trade-off between disorder and mobility. The polycrystalline ingot shows a giant positive magnetoresistance and Shubnikov de Haas oscillations, indicative of a high-mobility small electron pocket derived from the Ag s-electron band. Ni doping, which introduces chemical and lattice disorder, further enhances the electron mobility up to 90,000 cm2 V−1 s−1 at 10 K, leading not only to a larger magnetoresistance but also a better thermoelectric figure of merit. This Ag-based layered semimetal with a glassy lattice is a new type of promising thermoelectric material suitable for chemical engineering.

Authors: Veronica Augustyn, Jérémy Come, Michael A. Lowe, Jong Woung Kim, Pierre-Louis Taberna, Sarah H. Tolbert, Héctor D. Abruña, Patrice Simon & Bruce Dunn

Pseudocapacitance is commonly associated with surface or near-surface reversible redox reactions, as observed with RuO2·xH2O in an acidic electrolyte. However, we recently demonstrated that a pseudocapacitive mechanism occurs when lithium ions are inserted into mesoporous and nanocrystal films of orthorhombic Nb2O5 (T-Nb2O5; refs , ). Here, we quantify the kinetics of charge storage in T-Nb2O5: currents that vary inversely with time, charge-storage capacity that is mostly independent of rate, and redox peaks that exhibit small voltage offsets even at high rates. We also define the structural characteristics necessary for this process, termed intercalation pseudocapacitance, which are a crystalline network that offers two-dimensional transport pathways and little structural change on intercalation. The principal benefit realized from intercalation pseudocapacitance is that high levels of charge storage are achieved within short periods of time because there are no limitations from solid-state diffusion. Thick electrodes (up to 40 μm thick) prepared with T-Nb2O5 offer the promise of exploiting intercalation pseudocapacitance to obtain high-rate charge-storage devices.

Authors: Matthew D. Marcinkowski, April D. Jewell, Michail Stamatakis, Matthew B. Boucher, Emily A. Lewis, Colin J. Murphy, Georgios Kyriakou & E. Charles H. Sykes

Spillover of reactants from one active site to another is important in heterogeneous catalysis and has recently been shown to enhance hydrogen storage in a variety of materials. The spillover of hydrogen is notoriously hard to detect or control. We report herein that the hydrogen spillover pathway on a Pd/Cu alloy can be controlled by reversible adsorption of a spectator molecule. Pd atoms in the Cu surface serve as hydrogen dissociation sites from which H atoms can spillover onto surrounding Cu regions. Selective adsorption of CO at these atomic Pd sites is shown to either prevent the uptake of hydrogen on, or inhibit its desorption from, the surface. In this way, the hydrogen coverage on the whole surface can be controlled by molecular adsorption at a minority site, which we term a ‘molecular cork’ effect. We show that the molecular cork effect is present during a surface catalysed hydrogenation reaction and illustrate how it can be used as a method for controlling uptake and release of hydrogen in a model storage system.

Authors: Xi Yao, Yuhang Hu, Alison Grinthal, Tak-Sing Wong, L. Mahadevan & Joanna Aizenberg

Materials that adapt dynamically to environmental changes are currently limited to two-state switching of single properties, and only a small number of strategies that may lead to materials with continuously adjustable characteristics have been reported. Here we introduce adaptive surfaces made of a liquid film supported by a nanoporous elastic substrate. As the substrate deforms, the liquid flows within the pores, causing the smooth and defect-free surface to roughen through a continuous range of topographies. We show that a graded mechanical stimulus can be directly translated into finely tuned, dynamic adjustments of optical transparency and wettability. In particular, we demonstrate simultaneous control of the film’s transparency and its ability to continuously manipulate various low-surface-tension droplets from free-sliding to pinned. This strategy should make possible the rational design of tunable, multifunctional adaptive materials for a broad range of applications.

Authors: A. Dienst, E. Casandruc, D. Fausti, L. Zhang, M. Eckstein, M. Hoffmann, V. Khanna, N. Dean, M. Gensch, S. Winnerl, W. Seidel, S. Pyon, T. Takayama, H. Takagi & A. Cavalleri

Authors: J. Biscaras, N. Bergeal, S. Hurand, C. Feuillet-Palma, A. Rastogi, R. C. Budhani, M. Grilli, S. Caprara & J. Lesueur

Authors: T. An, V. I. Vasyuchka, K. Uchida, A. V. Chumak, K. Yamaguchi, K. Harii, J. Ohe, M. B. Jungfleisch, Y. Kajiwara, H. Adachi, B. Hillebrands, S. Maekawa & E. Saitoh

Authors: Arend M. van der Zande, Pinshane Y. Huang, Daniel A. Chenet, Timothy C. Berkelbach, YuMeng You, Gwan-Hyoung Lee, Tony F. Heinz, David R. Reichman, David A. Muller & James C. Hone

Authors: Daniel V. Esposito, Igor Levin, Thomas P. Moffat & A. Alec Talin

Authors: Tsuyoshi Sasaki, Yoshio Ukyo & Petr Novák

Authors: Sergio Bertazzo, Eileen Gentleman, Kristy L. Cloyd, Adrian H. Chester, Magdi H. Yacoub & Molly M. Stevens

Authors: Hiroaki Onoe, Teru Okitsu, Akane Itou, Midori Kato-Negishi, Riho Gojo, Daisuke Kiriya, Koji Sato, Shigenori Miura, Shintaroh Iwanaga, Kaori Kuribayashi-Shigetomi, Yukiko T. Matsunaga, Yuto Shimoyama & Shoji Takeuchi