Engineers at the University of California, Riverside, have talked about new developments in spintronic devices, which are thought to lead to a new technology for computing and data storage.
The researchers were led by Sandeep Kumar, an assistant professor of mechanical engineering. The engineers have developed methods to detect signals from spintronic components made of low-cost metals and silicon.
This will help overcome a major barrier to the wide application of spintronics. In the past, such devices relied on complex structures that used rare and expensive metals such as platinum.
Spintronic devices promise to solve major problems in today's electronic computers. Computers generally use massive amounts of electricity and generate heat that requires expending even more energy for cooling. By contrast, spintronic devices generate small amounts of heat and use relatively minuscule amounts of electricity.
Spintronic computers would also require no energy to maintain data in memory. They would also start instantly and have the potential to be far more powerful than today's computers.
Technology depends on property called “spin”
While electronics depends on the charge of electrons to generate the binary ones or zeroes of computer data, spintronics depends on the property of electrons called spin. Spintronic materials register binary data through the up or down spin orientation of electrons, like the north and south of bar magnets, in the materials.
A major barrier to the development of spintronics devices can be generating and detecting the infinitesimal electric spin signals in spintronic materials.
Usage of inexpensive and abundant materials
Kumar and colleagues talked about the technique of detecting the spin currents in a simple two-layer sandwich of silicon and a nickel-iron alloy called Permallo, in a paper published in the January issue of the scientific journal Applied Physics Letters.
All of the components are cheap and galore and could provide the basis for commercial spintronic devices. They also operate at room temperature. The researchers also demonstrated that they could generate a key property for spintronics materials, called antiferromagnetism, in silicon, in two other scientific papers.
The researchers said this opens an important road to commercial spintronics because silicon is inexpensive and can be produced using a mature technology. Kumar and his team reported detecting antiferromagnetism in the two types of silicon, used in transistors and other electronic components in the two papers.
Ferromagnetism is defined as the property of magnetic materials where the magnetic poles of the atoms are aligned in the same direction. On the other hand, antiferromagnetism is a property where the neighboring atoms are magnetically oriented in opposite directions. These so-called magnetic moments result from the spin of electrons in the atoms, and is elementary to the application of the materials in spintronics.
Combining the two types enables switching of current in such devices as transistors used in computer memories and other electronics. In further studies, Kumar and his colleagues are working to develop technology to switch spin currents on and off in the materials, with the final goal of creating a spin transistor. They are also working to generate larger, higher-voltage spintronic chips.
They predict their work could result in extremely low-power, compact transmitters and sensors, in addition to energy-efficient data storage and computer memories.