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!
Astronomers release most complete ultraviolet-light survey of nearby galaxies
18.05.2018 | NASA/Goddard Space Flight Center
A quantum entanglement between two physically separated ultra-cold atomic clouds
17.05.2018 | University of the Basque Country
So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics
Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...
The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...
A team led by Austrian experimental physicist Rainer Blatt has succeeded in characterizing the quantum entanglement of two spatially separated atoms by observing their light emission. This fundamental demonstration could lead to the development of highly sensitive optical gradiometers for the precise measurement of the gravitational field or the earth's magnetic field.
The age of quantum technology has long been heralded. Decades of research into the quantum world have led to the development of methods that make it possible...
Cardiovascular tissue engineering aims to treat heart disease with prostheses that grow and regenerate. Now, researchers from the University of Zurich, the Technical University Eindhoven and the Charité Berlin have successfully implanted regenerative heart valves, designed with the aid of computer simulations, into sheep for the first time.
Producing living tissue or organs based on human cells is one of the main research fields in regenerative medicine. Tissue engineering, which involves growing...
A team of scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg investigated optically-induced superconductivity in the alkali-doped fulleride K3C60under high external pressures. This study allowed, on one hand, to uniquely assess the nature of the transient state as a superconducting phase. In addition, it unveiled the possibility to induce superconductivity in K3C60 at temperatures far above the -170 degrees Celsius hypothesized previously, and rather all the way to room temperature. The paper by Cantaluppi et al has been published in Nature Physics.
Unlike ordinary metals, superconductors have the unique capability of transporting electrical currents without any loss. Nowadays, their technological...
02.05.2018 | Event News
13.04.2018 | Event News
12.04.2018 | Event News
18.05.2018 | Power and Electrical Engineering
18.05.2018 | Information Technology
18.05.2018 | Information Technology