Spin-Based Semiconductor Works at Room Temp.
ATHENS, Ohio, Oct. 4, 2006 -- Researchers have created an improved magnetic semiconductor that they said solves an electron problem spintronics scientists have been investigating for years.
Unlike classic or vintage electronics that operate on electronic charges, spin-based electronics focuses on the spin of electrons to carry and store information. Researchers predict spintronics will revolutionize the electronics industry by making devices faster, improving storage capacity and reducing the amount of power needed to run them.
Spintronics technology has not been widely applied yet, however, because scientists have had difficulty controlling, manipulating and measuring the electrons.
In a paper published online this week in Physical Review Letters, a team of Ohio University and Ohio State University (OSU) scientists led by postdoctoral fellow Erdong Lu have created an effective interface between a semiconductor and ferromagnetic metal. The two-layer "sandwich" of gallium nitride (GaN) and manganese gallium (MnGa) nearly eliminates any intermixing of the two layers and allows the spin to be "tuned."
"We found a way to grow the metal on the semiconductor. The crystalline match between the two materials was nearly perfect. The advantage of this finding is in the growth process. By adjusting the conditions of the growth, we can tune the spin," said Arthur Smith, associate professor of physics and astronomy and director of Ohio University's Nanoscale & Quantum Phenomena Institute.
Magnetization was controlled by monitoring a property of the growth called reconstruction. Through the monitoring process, researchers could predict the properties of the spin.
"It has to do with the ratio of manganese and gallium," Smith said.
The researchers also found that this new magnetic-semiconductor bilayer will operate at room temperature. Other materials have only worked at very low temperatures, which makes them impractical for commercial applications.
The research was funded by the National Science Foundation.
The primary author on the paper is Erdong Lu; co-authors are Smith and David Ingram, also of Ohio University, and J.W. Knepper and F.Y. Yang of OSU. For more information, visit: http://news.research.ohiou.edu
- That branch of science involved in the study and utilization of the motion, emissions and behaviors of currents of electrical energy flowing through gases, vacuums, semiconductors and conductors, not to be confused with electrics, which deals primarily with the conduction of large currents of electricity through metals.
- Acronym for self-aligned polysilicon interconnect N-channel. A metal-gate process that uses aluminum for the metal-oxide semiconductor (MOS) gate electrode as well as for signal and power supply connectors.
MORE FROM PHOTONICS MEDIA