Scientists at IBM Research and ETH Zurich in Switzerland report that they are the first to synchronize electron spins and image the formation of a persistent spin helix in a semiconductor. Until now, it was unclear whether electron spins could preserve encoded information long enough before rotating. This new work extends spin lifetime 30-fold, to 1.1 nanosec.
Multiferroics are expected to be applied to a new type of memory devices in which dielectric polarization is controlled by a magnetic field and magnetization is controlled by an electric field. However, multiferroic materials that function at room temperature are rare. In a breakthrough toward this goal, a team in Japan and the U.K. have achieved ferroelectric polarization without a magnetic field after discovering that they could swap out atoms and still maintain control of the multiferroic’s dielectric and magnetic properties.
Researchers at Argonne National Laboratory and in Switzerland have recently demonstrated the existence of long-lived charge-separated states in silver clusters. The stable charge-separated state, together with the fact that the clusters absorb light over a wide range of wavelengths, mean that the clusters represent a new and promising class of materials for solar energy applications.
Using a universal transfer approach, a team of engineers in Korea have built a flexible lithium-ion battery structured with high density inorganic thin films. The innovation has potential as an essential energy source for flexible displays.
In waveguides, such as those used in fiber optics, light has a tendency to reflect backwards, interfering with transmission of data. Today’s optical networks keep light from reflecting backward with devices called isolators. To help enable computer chips that operate with light, researchers at the Massachusetts Institute of Technology have invented a new metamaterial prevents electromagnetic waves from reflecting backward.
If recent research in Italy is an indication, the next generation of computing could be performed with silicene, an atomically thin form of silicon. The silicene structure consists of one atomic layer of silicon atoms and in this way it is analogous to graphene. With silicene, however, no modification is necessary to create a bandgap.
A recent study from Lawrence Berkeley National Laboratory offers the first direct observations and recordings of how electrons and holes respond to a charged impurity—a single Coulomb potential—placed on a gated graphene device. The results provide experimental support to the theory that interactions between electrons are critical to graphene’s extraordinary properties.
A research team has built an air-breathing battery that uses the chemical energy generated by the oxidation of iron plates that are exposed to the oxygen in the air—a process similar to rusting. The concept has been around for decades, but competing chemical reaction of hydrogen generation sucked away about 50% of the battery’s energy. Recent breakthroughs have lowered this loss to just 4%.
Computers often do not run as fast as they should because they are constantly transferring information between two kinds of memory: a fast, volatile memory connected to the CPU, and a slow, non-volatile memory that remembers data even when switched off. A special class of universal memory called spin-transfer torque magnetic random access memory (MRAM) being explored by researchers in Singapore could help avoid this bottleneck.
Plastic semiconductors have an important design flaw: The electronic current is influenced by poorly understood "charge traps" in the material. A new study by an international team of researchers reveals a common mechanism underlying these traps and provides a theoretical framework to design trap-free plastic electronics.
In a first for nanotechnology, a biophysicist in Switzerland has developed a method that measures not only the size of the particles but also their electrostatic charge. Up until the invention of this new approach, which relies on an “electrostatic trap”, it has not been possible to determine the charge of the particles directly.
Using a new side-view imaging technique, scientists in the U.K. have shown that their method for sandwiching individual graphene sheets between insulating layers in order to produce electrical devices works almost perfectly, even when more than 10 different layers are used to build the stack.
Researchers reporting fabrication of magnetic tunnel junctions using graphene between two ferromagnetic metal layers have demonstrated, for the first time, the use of graphene as a tunnel barrier—an electrically insulating barrier between two conducting materials through which electrons tunnel quantum mechanically. They accomplished the feat using a fully scalable photolithographic process.
Researchers from the University of Toronto and King Abdullah University of Science & Technology in Saudi Arabia have made a breakthrough in the development of colloidal quantum dot (CQD) films, reaching 7.0% in conversion efficiency. A combination of organic and inorganic chemistry was used to produce the most efficient CQD solar cell ever, an improvement of 37% over previous efforts.
Developed at RIKEN in Japan, a new type of transistor harnessing strong electron correlations can actually enable electrical switching of the state of matter. The device uses the electrostatic accumulation of electrical charge on the surface of a strongly-correlated material to trigger bulk switching of electronic state.
Ion irradiation creates an asymmetric potential or 'ratchet' for the main walls (visualised as light yellow spheres). The bit with a magnetic coating is shifted one position to
“Aerographite”, a jet-black network of porous, interwoven carbon tubes invented in northern Germany, weighs just 0.2 mg per cubic centimeter. This makes it 75 times lighter than Styrofoam, yet it is strong, ductile, and electrically conductive. It can also be compressed up to 95% and be pulled back to form without damage.
With the placement of a sheet of graphene, researchers at Columbia University have transformed an originally passive photonic integrated circuit into an active generator of microwave photonic signals. The device performs parametric wavelength conversion at telecommunication wavelengths, offering a glimpse at communications using very little power.
According to a Case Western Reserve University researcher, fuel cells are inefficient because the catalyst most commonly used to convert chemical energy to electricity is made of the wrong material. Platinum, he says, is like putting a resistor in the system. He also says existing explanations as to why platinum is the wrong material don’t do enough to explain its drawbacks.
A team of researchers from Drexel University has pioneered a new method for quickly and efficiently storing large amounts of electrical energy. Their solution is an electrochemical flow capacitor, which combines the strengths of batteries and supercapacitors while also negating the scalability problem.
A multi-institutional team has created the first artificial molecules whose chirality can be rapidly switched from a right-handed to a left-handed orientation with a beam of light. The breakthrough has potentially significant implications for the application of terahertz technologies across a wide range of fields, including reduced energy use for data-processing, homeland security, and ultrahigh-speed communications.
One bit of digital information stored on a hard disk currently consists of about 3 million magnetic atoms. Researchers in Germany and Japan have now developed a magnetic memory with one bit per molecule. Using an electric pulse deliver by atomic force microscopy, the metal-organic molecule can be switched reliably between a conductive, magnetic state and a low-conductive, non-magnetic state.
Researchers at Northwestern University, working with a team of scientists from the United States and abroad, have recently developed a type of electronics that can bend and stretch to more than 200% their original size, four times greater than is possible with today’s technology. The key is a combination of a porous polymer and liquid metal.
Imagine a kerosene lamp that continued to shine after the fuel was spent. Materials scientists at Harvard University have demonstrated an equivalent feat in clean energy generation with a solid-oxide fuel cell that converts hydrogen into electricity but can also store electrochemical energy like a battery. This fuel cell can continue to produce power for a short time after its fuel has run out.
Physicists in Germany have recently provided new insights into spintronics: In ultra-thin topological insulators, they have identified spin-polarized currents, which were first theoretically predicted six years ago. They have also presenteda method of application for the development of new computers.