Simulation: interaction of "spin
waves" emitted by two
nano-oscillators; © NIST
Scientists from the Commerce Department's National Institute of Standards and Technology (NIST) describe "locking" the dynamic magnetic properties of two nanoscale oscillators located 500 nanometers apart, boosting the power of the microwave signals given off by the devices.
While an individual oscillator has signal power of just 10 nanowatts, the output from multiple devices increases as the square of the number of devices involved. The NIST work suggests that small arrays of 10 nano-oscillators could produce signals of 1 microwatt or more, sufficient for practical use as reference oscillators or directional microwave transmitters and receivers in devices such as cell phones, radar systems and computer chips.
"These nanoscale oscillators could potentially replace much bulkier and expensive components in microwave circuits," says Matthew Pufall, one of the NIST researchers. "This is a significant advance in demonstrating the potential utility of these devices."
The NIST-designed oscillators consist of a sandwich of two magnetic films separated by a non-magnetic layer of copper. Passing an electrical current through the device causes the direction of its magnetization to switch back and forth rapidly, producing a microwave signal. The circular devices are 50 nanometers in diameter, about one-thousandth of the width of a human hair and hundreds of times smaller than the typical microwave generators in commercial use today. The devices are compatible with conventional semiconductor technology, which is expected to make them inexpensive to manufacture.
COMPAMED.de; Source: National Institute of Standards and Technology (NIST)