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.
University of Utah physicists developed an inexpensive, highly accurate magnetic field sensor for scientific and possibly consumer uses based on a “spintronic” organic thin-film semiconductor that basically is “plastic paint.” Its inventors say the new type of magnetometer also resists heat and degradation, works at room temperature and never needs to be calibrated.
An international team of researchers has used SLAC’s Linac Coherent Light Source (LCLS) to discover never-before-seen behavior by electrons in complex materials known for their strongly correlated structures. The unusual qualities of these materials, which include oxides such as striped nickelate, stem from the collective behavior of their electrons.
The performance of magnetic storage devices is limited by the way magnetic domains interact when in close proximity. Researchers in the U.K. have demonstrated that a honeycomb pattern of nano-sized magnets in a material known as spin ice introduces competition between neighboring magnets, and reduces the problems caused by these interactions by two-thirds.
Thermal stress can cause debonding between thin layers in microelectronics. Taking advantage of the force generated by magnetic repulsion, researchers have developed a new technique for measuring the adhesion strength between thin films of materials used in these devices, and they hope to apply the method improve solar cells or microelectromechanical devices.
During a six-experiment pulse this week, the previous world record for laboratory-produced magnetic fields was broken by Los Alamos National Laboratory researchers. The hundred-tesla field, about 2 million times Earth’s magnetic field was produced with the help of a 1,200-MJ motor generator.
Researchers at Helmholtz Center in Germany have developed a magnetic valve that could be an enabling technology for spintronics. The new structure allows for data to remain stored even after electric current has been cut, and memory in the valve can be re-written indefinitely.
Researchers at the Max Planck Institute have put together a sandwich of a ferroelectric layer between two ferromagnetic materials that responded to a short electric pulse. This changes the magnetic transport properties of the material in such a way that information can be placed in four states instead of just two. The potential increase in storage density is great.
Instead of using a magnetic field to record information on a magnetic medium, researchers in the U.K. recently harnessed much stronger internal forces and recorded information using only heat. This new method allows the recording of terabytes of information per second, hundreds of times faster than present hard drive technology.
On the shortest of time scales magnetic spins do not behave according to existing theory. According to a research team which has formulated a new theory of ultrafast magnetism, the spins are not coupled and move at a different pace, dependent on the element they're part of.
In magnetic recording media, each individual bit of information is stored over an area containing tens of grains. Engineers have until now had difficulty pushing beyond a one terabit per square inch limit by either reducing grain size or reducing the grains per bit. Researchers in Singapore have solved the problem by using something called bit-patterned media.
Although of purely scientific interest for now, a method that researchers at the SLAC National Accelerator Laboratory have invented to alter magnetic properties in manganese-oxide materials without heating them up could greatly speed up low-voltage, non-volatile computer memory.
A University of Bristol team has dissolved iron in liquid surfactant to create a soap that can be controlled by magnets. The discovery could be used to create cleaning products that can be removed after application and used in the recovery of oil spills at sea.
Physicists in Australia have observed a new kind of interaction that can arise between electrons in a single-atom silicon transistor. The study results open the door for new quantum electronic schemes in which it is the orbital nature of the electrons—and not their spin or their charge—that plays a major role.
Phase-change random access memory (PCRAM) is a promising technology for next-generation non-volatile memory, but it has been limited by room temperature efficiency. A research group in Japan recently invented a variation of PCRAM that achieves a magnetoresistance effect of more than 2000% at room temperature and higher, and doesn’t require the use of magnetic elements such as cobalt and platinum.
Scientists from IBM and the German Center for Free-Electron Laser Science have built the world's smallest magnetic data storage unit. It uses just twelve atoms per bit, the basic unit of information, and squeezes a whole byte (8 bits) into as few as 96 atoms.
Using powerful magnets to levitate fruit flies can provide vital clues to how biological organisms are affected by weightless conditions in space, researchers at The University of Nottingham say. The team of scientists has shown that simulating weightlessness in fruit flies here on earth with the use of magnets causes the flies to walk more quickly.
In the 1950s, researchers first observed phonon drag, a thermoelectric effect that occurs as electrons move past atoms in a solid. Physicists predicted an analogous phenomenon in magnetic materials, but aside from indirect indications of its existence, magnon drag has been elusive. Until now.