Featured
-
-
Research Highlights |
Materials science: Graphene layers made to order
-
Research Highlights |
Materials science: Spinning yarns of nanotubes
-
News & Views |
The conducting face of an insulator
Stacking two oxide insulators together is known to yield a conducting system at the interface between the oxides. But the discovery that simply cleaving such an insulator yields the same outcome is unexpected. See Letter p.189
- Elbio Dagotto
-
Letter |
Two-dimensional electron gas with universal subbands at the surface of SrTiO3
An exotic two-dimensional electron gas (2DEG) forms at oxide interfaces based on SrTiO3, but the precise nature of the 2DEG has remained elusive. In a systematic study using angle-resolved photoemission spectroscopy (ARPES), new insights into the electronic structure of the 2DEG are obtained. The findings shed light on previous observations in SrTiO3-based heterostructures and suggest that different forms of electron confinement at the surface of SrTiO3 lead to essentially the same 2DEG.
- A. F. Santander-Syro
- , O. Copie
- & M. J. Rozenberg
-
Letter |
Nanoscale chemical tomography of buried organic–inorganic interfaces in the chiton tooth
Many biomineralized tissues (such as teeth and bone) are hybrid inorganic–organic materials whose properties are determined by their convoluted internal structures. Now, using a chiton tooth as an example, this study shows how the internal structural and chemical complexity of such biomaterials and their synthetic analogues can be elucidated using pulsed-laser atom-probe tomography.
- Lyle M. Gordon
- & Derk Joester
-
Research Highlights |
Materials science: Magnetic gel delivers drugs
-
News & Views |
Electrons spin in the field
Nanowires are candidates for enabling the exchange of quantum information between light and matter. The rapid control of a single electron spin by solely electrical means brings this possibility closer. See Letter p.1084
- David J. Reilly
-
Letter |
Spin–orbit qubit in a semiconductor nanowire
Motion of electrons can influence their spins through a fundamental effect called the spin–orbit interaction. Here, a spin–orbit quantum bit (qubit) is implemented in an indium arsenide nanowire, which should offer significant advantages for quantum computing. The spin–orbit qubit is electrically controllable, and information can be stored in the spin. Moreover, nanowires can serve as one dimensional templates for scalable qubit registers, and are suited for both electronic and optical devices.
- S. Nadj-Perge
- , S. M. Frolov
- & L. P. Kouwenhoven
-
Letter |
Mantle superplasticity and its self-made demise
The unusual capability of solid crystalline materials to deform plastically (known as superplasticity) has been found in metals and even ceramics; however, no experimental studies have yet to demonstrate this behaviour in geological materials. It is now demonstrated that some synthetic rocks, which are good analogues for Earth's mantle, undergo homogeneous elongation up to 500% under subsolidus conditions. Calculations show that such superplastic flow in the mantle is inevitably accompanied by significant grain growth that can change fine-grained rocks to coarse-grained aggregates, resulting in increasing mantle viscosity and finally termination of superplastic flow.
- Takehiko Hiraga
- , Tomonori Miyazaki
- & Hidehiro Yoshida
-
News & Views |
Model's reputation restored
The structure of a mineral has been validated, ending the controversy about its potential usefulness as a model of an unusual magnetic lattice. This model might provide insight into superconductivity.
- Mark A. de Vries
- & Andrew Harrison
-
News & Views |
Pleated crystals
A neat study that involves placing colloidal particles on curved oil-glycerol interfaces reveals a new form of crystal defect. The defect is called a pleat, by analogy to the age-old type of fabric fold. See Letter p.947
- Francesco Stellacci
- & Andreas Mortensen
-
Letter |
Atom-by-atom spectroscopy at graphene edge
Electron microscopy has advanced to the stage where individual elements can be identified with atomic resolution. Here it is shown to be possible to get fine-structure spectroscopic information of individual light atoms such as those of carbon, and so also probe their chemical state. This capability is illustrated by investigating the edges of a graphene sample, where it is possible to discriminate between single-, double- and triple-coordinated carbon atoms.
- Kazu Suenaga
- & Masanori Koshino
-
Letter |
Pleats in crystals on curved surfaces
Hexagons can easily tile a flat surface, but not a curved one. Defects with topological charge (such as heptagons and pentagons) make it easier to tile curved surfaces, such as soccer balls. Here, a new type of defect is reported that accommodates curvature in the same way as fabric pleats. The appearance of such defects on the negatively curved surfaces of stretched colloidal crystals are observed. The results will facilitate the exploration of general theories of defects in curved spaces, the engineering of curved structures and novel methods for soft lithography and directed self-assembly.
- William T. M. Irvine
- , Vincenzo Vitelli
- & Paul M. Chaikin
-
Research Highlights |
Materials science: Antiseptic silver slivers
-
Research Highlights |
Materials: Controlling water on synthetic silk
-
News & Views |
How the cuprates hid their stripes
Extensive mapping of local electronic structure in copper oxide superconductors reveals fluctuating stripe-like electron patterns that appear as a high-temperature precursor to superconductivity. See Letter p.677
- Kathryn A. Moler
-
Letter |
Fluctuating stripes at the onset of the pseudogap in the high-Tc superconductor Bi2Sr2CaCu2O8+x
A long-standing question has been the interplay between pseudogap, which is generic to all hole doped copper oxide superconductors, and stripes, whose static form occurs in only one family of copper oxides over a narrow range of the phase diagram. This study reports observations of the spatial reorganization of electronic states with the onset of the pseudogap state at T* in the high temperature superconductor Bi2Sr2CaCu2O8+x using scanning tunnelling microscopy. The onset of the pseudogap phase coincides with the appearance of electronic patterns that have the predicted characteristics of fluctuating stripes. The experiments indicate that stripes are a consequence of pseudogap behaviour rather than its cause.
- Colin V. Parker
- , Pegor Aynajian
- & Ali Yazdani
-
Research Highlights |
Material science: Stopping ice before it forms
-
Feature |
Small science yields big growth
Nanomaterials have evolved from innovation to application — and the career possibilities have blossomed.
- Corinna Wu
-
News & Views |
Peptides as biological semiconductors
A simple peptide that assembles into desirable nanoscale structures is a striking example of how the whole can be greater than the sum of its parts. What's more, the assembly process is controllably reversible.
- Charlotte A. E. Hauser
- & Shuguang Zhang
-
News |
Chilled light enters a new phase
First Bose–Einstein condensate of photons could help build solar cells and lasers.
- Zeeya Merali
-
Letter |
Snapshots of cooperative atomic motions in the optical suppression of charge density waves
The development of table-top femtosecond electron diffraction sources in recent years has opened up a new way to observe atomic motions in crystalline materials undergoing structural changes. Here, the technique is used to study the charge density wave material 1T-TaS2, where a modulation of the electron density is accompanied by a periodic lattice distortion. In this femtosecond electron diffraction experiment, where atomic motions are observed in response to a 140 femtosecond optical pulse, the periodic lattice distortion is found to collapse on an exceptionally fast timescale (about 250 femtoseconds), indicative of an electronically driven process involving a highly cooperative process.
- Maximilian Eichberger
- , Hanjo Schäfer
- & R. J. Dwayne Miller
-
Research Highlights |
Materials science: Graphene meets fluorine
-
News & Views |
Thin films with a hidden twist
Many naturally occurring substances have a 'handedness' that enables them to interact highly specifically with matter or light. The helical features responsible for this can now be replicated in solid, porous films. See Letter p.422
- Andreas Stein
-
Letter |
Free-standing mesoporous silica films with tunable chiral nematic structures
Some beetle shells exhibit iridescence owing to the chiral organization of chitin making up the beetle's exoskeleton. Inspired by this, these authors fabricate thin glass films with helical pores introduced using a renewable cellulose template. The chiral structure allows the material, which can be free-standing, to selectively reflect light at a specific wavelength that can be tuned across the visible spectrum by altering the ratio of silica to cellulose during synthesis.
- Kevin E. Shopsowitz
- , Hao Qi
- & Mark J. MacLachlan
-
Research Highlights |
Materials science: Film bends with light
-
News & Views |
A diverse printed future
An approach that entails printing compound-semiconductor ribbons on a silicon substrate offers the means to build nanoscale transistors that can be switched on and off much more effectively than their bulk analogues. See Letter page 286
- John A. Rogers
-
Letter |
Growth of graphene from solid carbon sources
The past few years have seen a spectacular growth of interest in graphene. Efforts to produce large sheets of monolayer (or few-layer) graphene could receive a welcome boost from the simple procedure reported by these authors. They show how baking various solid carbon sources (for example polymer films) deposited on a metal catalyst substrate can produce either pristine graphene or doped graphene in a single step.
- Zhengzong Sun
- , Zheng Yan
- & James M. Tour
-
Letter |
Ultrathin compound semiconductor on insulator layers for high-performance nanoscale transistors
A potential route to enhancing the performance of electronic devices is to integrate compound semiconductors, which have superior electronic properties, within silicon, which is cheap to process. These authors present a promising new concept to integrate ultrathin layers of single-crystal indium arsenide on silicon-based substrates with an epitaxial transfer method borrowed from large-area optoelectronics. With this technique, the authors fabricate thin-film transistors with excellent device performance.
- Hyunhyub Ko
- , Kuniharu Takei
- & Ali Javey
-
Letter |
Holographic three-dimensional telepresence using large-area photorefractive polymer
Holographic displays can produce truly three-dimensional (3D) images, but have so far been unable to update images fast enough. These authors have adapted a previous technique, based on holographic stereographic recording with a photorefractive polymeric material as the recording medium, to produce a quasi-real-time holographic display that can refresh its images every two seconds, and use it to demonstrate the possibility of 3D telepresence. Improvements could bring applications in telemedicine, prototyping, advertising, updatable 3D maps and entertainment.
- P.-A. Blanche
- , A. Bablumian
- & N. Peyghambarian
-
Research Highlights |
Physics: Insulator insight into constant
-
Letter |
Detecting excitation and magnetization of individual dopants in a semiconductor
Isolated magnetic atoms doped into a semiconductor represent an interesting system for spintronics applications and a possible means of constructing quantum bits. So far, however, it has not been possible to study the correlation between the local atomic structure and the dopant's magnetic properties. Here, sensitive scanning probe techniques have been developed that allow the spin excitations of individual magnetic dopants within a two-dimensional semiconductor system to be measured.
- Alexander A. Khajetoorians
- , Bruno Chilian
- & Roland Wiesendanger
-
Letter |
Quantum tunnelling of the magnetization in a monolayer of oriented single-molecule magnets
Single-molecule magnets are molecular complexes with magnetic bistability, and recently it was shown that such a magnetic memory effect is retained for Fe4 clusters when they are wired to a gold surface. These authors have tailored the clusters to have a preferential orientation and form a self-assembled monolayer on the surface. It then becomes possible to observe quantum tunnelling of the magnetization, which shows up as steps in the magnetic hysteresis loop.
- M. Mannini
- , F. Pineider
- & R. Sessoli
-
News & Views |
Beyond the confines of templates
The use of templates to control the morphology of nanostructures is a powerful but inflexible technique. A template that is remodelled during synthesis suggests fresh opportunities for fabricating new nanostructures.
- Younan Xia
- & Byungkwon Lim
-
Letter |
Nonlinear electrophoresis of dielectric and metal spheres in a nematic liquid crystal
Electrophoresis is a motion of charged dispersed particles relative to a fluid in a uniform electric field. Here it is described how an anisotropic fluid — a nematic liquid crystal — can lead to motion of both charged and neutral particles, even when they are perfectly symmetrical, in any type of electric field. The phenomenon is caused by a distortion in the orientation of the liquid crystals around the particles. The approach could see applications in, for example, display technologies and colloidal assembly and disassembly.
- Oleg D. Lavrentovich
- , Israel Lazo
- & Oleg P. Pishnyak
-
News |
Flexible LEDs to boost biomedicine
Bendy, waterproof electronics made with conventional semiconductors could be implanted in the body.
- Jon Cartwright
-
News & Views |
Seeing the spin through
Interfaces can have quite different properties from those of their constituent materials. But it's surprising that the adsorption of a single organic molecule onto a magnetic surface can drastically modify that surface's magnetism.
- Stefano Sanvito
-
Letter |
Geometry-induced electrostatic trapping of nanometric objects in a fluid
Many fields would benefit from a simple and efficient method of trapping single particles, but this is extremely difficult when dealing with nanometre-sized objects in solution. These authors show that grooves and pockets etched into fluidic channels that acquire a charge on exposure act as highly effective electrostatic traps. With further optimization, this trapping concept could allow contact-free confinement of single proteins and nanoparticles, their sorting and fractionation, or assembly into high-density arrays.
- Madhavi Krishnan
- , Nassiredin Mojarad
- & Vahid Sandoghdar
-
News |
Graphene speeds pair to Stockholm win
Research on carbon sheets scores Nobel Prize in Physics.
- Geoff Brumfiel
-
Letter |
Seismic evidence of negligible water carried below 400-km depth in subducting lithosphere
These authors test whether patterns of seismicity and the stabilities of potentially relevant hydrous phases are consistent with a wet lithosphere. They show that there is nearly a one-to-one correlation between the dehydration of minerals and seismicity at depths less than ∼250 km, but no correlation at greater depths. They conclude that subducting slabs must be essentially dry by 400-km depth and thus do not provide a pathway for significant amounts of water to enter the mantle transition zone or the lower mantle.
- Harry W. Green II
- , Wang-Ping Chen
- & Michael R. Brudzinski
-
News |
Quantum computers move a step closer
Successes at entangling three-circuit systems brighten the prospects for solid-state quantum computing.
- Eugenie Samuel Reich
-
News & Views |
Paired in one dimension
The trend towards using ultracold atomic gases to explore emergent phenomena in many-body systems continues to gain momentum. This time around, they have been used to explore novel pairing mechanisms in one dimension. See Letter p.567
- Immanuel Bloch
-
Letter |
Preparation and measurement of three-qubit entanglement in a superconducting circuit
Quantum entanglement is a key resource for technologies such as quantum communication and computation. A major question for solid-state quantum information processing is whether an engineered system can display the three-qubit entanglement necessary for quantum error correction. A positive answer to this question is now provided. A circuit quantum electrodynamics device has been used to demonstrate deterministic production of three-qubit entangled states and the first step of basic quantum error correction.
- L. DiCarlo
- , M. D. Reed
- & R. J. Schoelkopf
-
Letter |
Water and its influence on the lithosphere–asthenosphere boundary
What defines the boundary between the Earth's lithosphere and asthenosphere? Here it is shown experimentally that the instability of the hydrous mineral pargasite at depths greater than about 90 km causes a sharp drop in the water-storage capacity of a fertile upper-mantle mineralogy, and accordingly a sharp drop in its solidus temperate. This effect might define the lithosphere–asthenosphere boundary.
- David H. Green
- , William O. Hibberson
- & Anja Rosenthal
-
Research Highlights |
Biomimetics: Material monitors mugginess
-
Letter |
Production and application of electron vortex beams
It was demonstrated recently that passing electrons through a spiral stack of graphite thin films generates an electron beam with orbital angular momentum — analogous to the spiralling wavefronts that can be introduced in photon beams and which have found widespread application. Here, a versatile holographic technique for generating these twisted electron beams is described. Moreover, a demonstration is provided of their potential use in probing a material's magnetic properties.
- J. Verbeeck
- , H. Tian
- & P. Schattschneider
-
Research Highlights |
Materials science: Skin-like sensors
-
Letter |
High-resolution tunnelling spectroscopy of a graphene quartet
In graphene, two particular sets of electrons exist that have a fourfold energy degeneracy. To study the corresponding four quantum states comprising a Landau level, these authors perform measurements on epitaxial graphene at 10 millikelvin. They take spectral 'fingerprints' of the Landau levels, showing in detail how they evolve with magnetic field and how they split into the four separate quantum states. They also observe states with Landau level filling factors of 7/2, 9/2 and 11/2.
- Young Jae Song
- , Alexander F. Otte
- & Joseph A. Stroscio
-
News & Views |
Holes with an edge
Tiny holes have been drilled through individual layers of graphene — atomically thin sheets of carbon — using an electron beam. These nanopores might be useful for the ultrarapid sequencing of single DNA molecules.
- Hagan Bayley