Researchers from the UB and the New York University show how to create and control spin waves in nanostructures
A team of physicists from the University of Barcelona (UB) and the New York University (NYU) has developed a method to control the movements occurring within magnetic materials, which are used to store and carry information. The breakthrough could simultaneously bolster information processing while reducing the energy necessary to do so.
Their method, reported in the most recent issue of the journal Nature Nanotechnology, manipulates the spin waves that move in magnetic materials. Physically, these spin waves are much like water waves propagated on the surface of an ocean. However, like electromagnetic waves (i.e., light and radio waves), spin waves can efficiently transfer energy and information from place to place.
A team of physicists from the University of Barcelona (UB) and the New York University (NYU) has developed a method to control the movements occurring within magnetic materials, which are used to store and carry information. The breakthrough could simultaneously bolster information processing while reducing the energy necessary to do so.
Their method, reported in the most recent issue of the journal Nature Nanotechnology, manipulates the spin waves that move in magnetic materials. Physically, these spin waves are much like water waves propagated on the surface of an ocean. However, like electromagnetic waves (i.e., light and radio waves), spin waves can efficiently transfer energy and information from place to place.
The main objective to be fulfilled by scientists is to develop a means to create and control these waves. In the study, UB and NYU researchers demonstrate how spin waves can be trapped by means of magnetic ʻdropletsʼ, which is a step towards this control.
“Spin waves have great potential to improve information processing and make it more energy efficient,” says Ferran Macià, researcher at the UBʼs Department of Fundamental Physics and first author of the paper. “Our results show that itʼs possible to both create and store spin wave energy in remarkably small spaces. The next steps are to understand how far these waves can propagate and how best to encode information in them”.
The studyʼs authors included Andrew Kent, from the New York University, and Dirk Backes, former NYU postdoctoral researcher and presently at the University of Cambridge.
Magnetic ʻdropletsʼ to trap spin waves
In the study, researchers conducted a series of experiments in which they built nanometre scale electrical contacts to inject spin-polarized electrical currents into magnetic materials —a process developed to create and control the movements of its spin waves. Specifically, by blending different magnetic forces they were able to trap them in a specific area, forming magnetic ʻdropletsʼ. Future research, scientists say, would then focus on ways to move this localized energy or release it in the form of propagating spin waves.
“Weʼve known that spin waves can propagate, but weʼve shown in this study that you can control them so they will localize in a specific spot”, explains Macià. “By changing the mix of magnetic forces on these droplets —for example with a electrical current or magnetic field—we should be able to get them to emit spin-waves, perhaps as energy bursts, that can encode information”.
F. Macià, D. Backes i A. D. Kent. “Stable Magnetic Droplet Solitons in Spin Transfer Nanocontacts”. Nature Nanotechnology, 17 November 2014.