Physicists understand perfectly well why a fridge magnet sticks to certain metallic surfaces. But there are more exotic forms of magnetism whose properties remain unclear, despite decades of intense research. Now, researchers at ETH Zurich in Switzerland have developed a quantum simulator that can arrange atoms in a way that they mimic the behavior of electrons in magnetic materials.
Magnetic memories store bits of information in discrete units whose electron spins all line up in parallel, pointing one way or the opposite to signify a one or a zero. At the Advanced Light Source, Lawrence Berkeley National Laboratory scientists recently joined an international team to advance a new concept in magnetic memory, one in which spin orientation is controlled in magnetic nanodisks, allowing multi-bit storage.
Research on bursts of energy within magnetic systems dates back two decades. But scientists haven't been able to measure and understand what prompts this phenomenon, known as "magnetic deflagration." New York University physicists have uncovered how energy is released and dispersed in magnetic materials in a process akin to the spread of forest fires.
Scientists already know that graphene has extraordinary conductive, mechanical, and optical properties. Now it is possible to give it one more property: magnetism. Researchers in Spain have used a technique that involves growing a precise graphene film over a ruthenium single crystal inside an ultra high vacuum chamber where organic semiconducting molecules are evaporated on the graphene surface.
From powerful computers to super-sensitive medical and environmental detectors that are faster, smaller, and use less energy—yes, we want them, but how do we get them? In research that is helping to lay the groundwork for the electronics of the future, University of Delaware scientists have confirmed the presence of a magnetic field generated by electrons which scientists had theorized existed, but that had never been proven until now.
Magnetic vortices typically occur in nanometer-scale magnetic disks, which are studied for their potential roles in wireless data transmission. So far, magnetic vortex states have been observed only within a plane, but recently researchers in Europe have discovered 3D magnetic vortices for the first time in a specially designed stack of magnetic disks.
Many collisions occur between asteroids and other objects in our solar system, but scientists are not always able to detect or track these impacts from Earth. Space scientists at the University of California, Los Angeles have now devised a way to monitor these types of collisions in interplanetary space by using a new method to determine the mass of magnetic clouds that result from the impacts.
Excess heat, like that generated by extended use of a computer or other device, naturally creates what is known as a spin wave that can move a domain wall, the dividing line between magnetic materials that point in different directions. Using this phenomenon, scientists in California have demonstrated how to add power to a spintronics device using electron spin rather than electron charge.
A University of Missouri engineer has built a system that is able to launch a ring of plasma as far as two feet. Plasma is commonly created in the laboratory using powerful electromagnets, but previous efforts to hold the super-hot material through air have been unsuccessful. The new device does this by changing how the magnetic field around the plasma is arranged.
The use of femtosecond light pulses—the fastest man-made event—with photon energies ranging from X-rays (as used for instance at the HZB femto-slicing facility) to terahertz spectral range has proved to be an indispensable tool in ultrafast spin and magnetization dynamics studies. Researchers have recently demonstrated a simple but powerful way of manipulating the spins at these unprecedented speeds.
Scheduled for launch in late 2013, the Mars Atmosphere and Volatile Evolution (MAVEN) mission will carry a sensitive magnetic-field instrument built and tested by a team at NASA’s Goddard Space Flight Center. Very little magnetic field traces remain on Mars, which is forcing NASA to eliminate all magnetic traces from its spacecraft. The magnetometer may help determine the history of the loss of atmospheric gases to space through time, providing answers about Mars’ climate evolution.
A team that includes researchers from Sweden has successfully created a magnetic soliton, a spin torque-generated nano-droplet that could lead to technological innovation in such areas as mobile telecommunications. This construct was first theorized 35 years ago and scientists have long believed that they exist in magnetic environments, but until now they had never been observed
Researchers in France and Germany have found a way to combine both carbon nanotubes with magnetic molecules on the atomic level to build a quantum mechanical system that acts as a vibration sensor. In their experiment the researchers used a carbon nanotube that was mounted between two metal electrodes, spanned a distance of about 1 µm, and could vibrate mechanically.
Electromagnetic devices, from power drills to smart-phones, require an electric current to create the magnetic fields that allow them to function. But researchers at the University of California, Los Angeles have developed a method for switching tiny magnetic fields on and off with an electric field—a sharp departure from the traditional approach of running a current through a wire. The new composite can control magneto-electric activity at a scale of just 10 nm.
Electric rocket engines known as Hall thrusters, which use a super high-velocity stream of ions to propel a spacecraft in space, have been used successfully onboard many missions for half a century. Erosion of the discharge channels walls, however, has limited their application to the inner solar system. A research team at Caltech's Jet Propulsion Laboratory has found a way to effectively control this erosion by shaping the engine's magnetic field in a way that shields the walls from ion bombardment.
Engineers at the Korea Advanced Institute of Science and Technology (KAIST) and the Korea Railroad Research Institute have designed a wireless technology that can be applied to high capacity transportation systems such as railways, harbor freight, and airport transportation, and logistics. The technology supplies 60 kHz and 180 kW of power remotely to transport vehicles at a stable, constant rate.
Researchers have recently demonstrated magnetic resonance imaging (MRI) on the molecular scale through the use of artificial atoms, diamond nanoparticles doped with nitrogen impurity. Conventional MRI responds to the magnetic fields of atomic nuclei, but this new method improves resolution nearly one million times, allowing scientists to probe very weak magnetic fields such as those generated in some biological molecules and even proteins.
When migrating, sockeye salmon typically swim up to 4,000 miles into the ocean and then, years later, navigate back to the upstream reaches of the rivers in which they were born to spawn their young. Scientists have long wondered how salmon find their way to their home rivers over such epic distances. A new study suggests that salmon find their home rivers by sensing the rivers' unique magnetic signature.
Research by an international team of physicists has produced new methods for controlling magnetic order in a particular class of materials known as "magnetoelectrics", which have their magnetic and electric properties couple to each other. This link offers the possibility of controlling electric behavior with a magnetic signal, or vice versa. Scientists recently demonstrated this ability in europium-titanium oxide.
Researchers in Switzerland have designed tiny vessels that are capable of releasing active agents in the body. These “nanovehicles” are made from a liposome just 100 to 200 nm in diameter. By attaching magnetic iron oxide nanoparticles to the surface, scientists are able to target the vessel, heating it up to release the drug.
Physicists have recently demonstrated that the application of a very strong alternating electric field to thin liquid crystal cells leads to a new distinct nonlinear dynamic effect in the response of the cells. Researchers were able to explain this result through spatio-temporal chaos theory. The finding has implications for the operation of liquid crystal devices because their operation depends on electro-optic switch phenomena.
The Barkhausen Effect is the noise in the magnetic output of a ferromagnet when the magnetizing force applied to it is changed. Almost 100 years after its initial discovery, a team of scientists in Alberta have harnessed this effect as a new kind of high-resolution microscopy for the insides of magnetic materials.
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.