Groups of nanoscale magnetic oscillators are known to synchronize their individual 10-nanowatt signals to achieve a signal strength equal to the square of the number of devices. Now scientists at the National Institute of Standards and Technology (NIST), Seagate Research Center (Pittsburgh, Pa.) and Hitachi Global Storage Technologies (San Jose, Calif.) have discovered how--the oscillators accomplish this feat by communicating by means of "spin waves," their magnetic emissions caused by oscillating patterns in the spin of electrons.
The discovery, reported in the Aug. 25 issue of Physical Review Letters, provides a tool for designing "spintronic" devices, which are based on the spin of electrons instead of their charge as in conventional electronics. The NIST oscillators--nanoscale electrical contacts applied to sandwiches of two magnetic films separated by a non-magnetic layer of copper--are hundreds of times smaller than typical commercial microwave generators and potentially could replace much bulkier and expensive components.
The NIST team previously reported "locking" the signals of two oscillators [www.nist.gov/public_affairs/releases/nanooscillators.htm] but were not sure why this occurred. They suspected spin waves, which propagate through solid magnetic materials, or magnetic fields, which propagate through air or a vacuum. So they did an experiment by making two oscillators on the same slab of magnetic multilayer, locking their signals, and then cutting a gap in the solid material between the two devices. The locking stopped.
Lead author Matthew Pufall of NIST compares spin wave locking to dropping two rocks in different sides of a pool of water, so that ripples propagate outward from each spot until they meet and merge. Each oscillator shifts the frequency of its own spin waves to match that of the incoming wave; this "frequency pulling" gets stronger as the frequencies get closer together, until they lock. Each oscillator also adjusts the peaks and troughs of its wave pattern to the incoming wave, until the two sets of waves synchronize.
Laura Ost | EurekAlert!
Scientists discover particles similar to Majorana fermions
25.10.2016 | Chinese Academy of Sciences Headquarters
Light-driven atomic rotations excite magnetic waves
24.10.2016 | Max-Planck-Institut für Struktur und Dynamik der Materie
Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.
This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...
Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion
Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
25.10.2016 | Earth Sciences
25.10.2016 | Power and Electrical Engineering
25.10.2016 | Process Engineering