In science, just like in life, sometimes creating the most effective organization depends on being able to handle just a bit of chaos first. Scientists at Argonne National Laboratory have used alternating magnetic fields to control the behavior of "spin vortices" trapped in small dots made from iron and nickel that can be magnetized in two separate ways.
Following up on earlier theoretical predictions, Massachusetts Institute of Technology researchers have now demonstrated experimentally the existence of a fundamentally new kind of magnetic behavior, adding to the two previously known states of magnetism.
Evaporative cooling has long been used to cool atoms, but it has never before been done by molecules—two different atoms bonded together. Achieving a goal considered nearly impossible, JILA physicists have done this, chilling a gas of molecules to very low temperatures by adapting the familiar process by which a hot cup of coffee cools.
A team of scientists has studied magnons in a material that becomes helimagnetic below about 30 K: iron silicide doped with cobalt. They investigated how helimagnons evolve as the temperature increases, destroying the magnetic order, as well as how the magnetic phases are affected by an external magnetic field.
Inductors are essential components of integrated circuits. The sprawling metal spirals store magnetic energy, acting as a buffer against changes in current and modulating frequency. However, because inductance depends on the number of coils, they take up a lot of space. Researchers have recently build a 3D rolled-up inductor with a footprint more than 100 times smaller without sacrificing performance.
Engineers in Texas have adopted the nanoscale fabrication technique of directed self-assembly to increase the surface storage density of hard disk drives. The method, which relies on block copolymers, is able to organize magnetic dots into patterns far finer than existing methods. And it does so without risking the integrity of the magnetic fields.
In a tornado, the individual air particles do not necessarily rotate on their own axis, but the air suction overall creates a powerful rotation. Similar vortex beams are being used in electron microscopy to allow researchers to determine the angular momentum of materials under examination. This ability provides valuable information about a material’s magnetic field. Researchers in Austria have recently produced particularly intense vortex beams.
For the first time, three separately found extreme Earth events have been compared by researchers who now believe they may be linked. About 41,000 years ago, a complete and rapid reversal of the geomagnetic field occurred, lasting for just a few hundred years. Around the same time, a super volcano erupted and major climate changes occurred.
Magnetotactic bacteria are organisms which develop membrane-encapsulated nano-particles known as magnetosomes. Although these microbes were first discovered in 1975, the production of their magnetite crystals is still not fully understood. A researcher in the U.K. is now using computational simulation tools to discover how magnetosomes allow bacteria to orient themselves along the Earth’s magnetic field lines.
Magnetized iron can be demagnetized extremely quickly (just a few hundred femtoseconds) when it is radiated with laser light pulses. Researchers in Europe have used x-ray light to reveal a new cause for this loss of magnetism. They found that electrons can move very quickly between areas with different magnetization and polarization, thereby influencing the demagnetization of the material. The effect could play a decisive role in reducing the size of magnetic memories.
A University of Delaware research team’s exploration of paramagnetic colloids—microscopic particles that are mere hundredths the diameter of a human hair—has produced the possibility that computer chips could one day build themselves in a scalable fashion. By applying a magnetic field to the colloids, the team build organized crystalline lattices from random solids.
An international team of researchers have demonstrated a microscopy method to identify magnetic defects in an array of magnetic nanostructures. The method represents an important step towards identifying, measuring, and correcting the magnetic properties of defective devices in future information storage technologies.
Massachusetts Institute of Technology researchers have developed a new technique for magnetically separating oil and water that could be used to clean up oil spills. They believe that, with their technique, the oil could be recovered for use, offsetting much of the cleanup cost.
A team of researchers at in Japan has demonstrated a new material that promises to eliminate loss in electrical power transmission. Their methodology for solving this classic energy problem is based on a highly exotic type of magnetic semiconductor first theorized less than a decade ago—a magnetic topological insulator.
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.
Traditional mechanical couplings and gears require lubrication, generate heat, emit vibrations and sound, suffer from structural wear and require significant maintenance. Correlated Magnetics Research has been tasked with a Small Business Innovation Research grant to design and develop high-torque magnetic couplings to produce quiet, maintenance free, power-transfer linkages for Naval systems and industrial applications.
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.
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.
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
Migratory birds and fish use the Earth’s magnetic field to find their way. Researchers have recently identified cells with internal compass needles for the perception of the field—and can explain why high-tension cables perturb the magnetic orientation.
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.
Scientists have managed to switch on and off the magnetism of a new material using quantum mechanics, making the material a test bed for future quantum devices. The team of researchers found that the material, a transparent salt, did not suffer from the usual complications of other real magnets, and exploited the fact that its quantum spins interact according to the rules of large bar magnets.
A breakthrough in control of nanoscale molecular magnets has been made at a German research institution. Despite their dense packing in a molecular layer, Dr. Thiruvancheril Gopakumar was able to use a scanning tunneling microscope to switch individual molecules between two magnetic states.
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.