Everyone knows that electrons have a charge and spin. Typical electronic devices operate by taking advantage of that charge. Argonne National Laboratories in Argonne, Ill., however, is investigating "spintronic" devices—that is, devices that utilize an electron's charge and spin.
Aligning the spins of a material's electrons along a common direction, rather than letting them point randomly in all directions, magnetizes the material. By doing so, the magnetized elements of electronic devices would stay magnetized. Replacing the semiconductor components in a computer with magnetic components, then, would have a number of advantages.
When an electronic device's power is cut off, for example, information stored via electronic charges is lost. But a computer with an all-magnetic RAM would always retain its information. Also, there would be no "boot up" waiting period when the power is first activated.
Researchers have attempted such devices before, but magnetic RAM has been difficult to achieve. The individual memory elements are addressed by flipping their spins up or down to yield the zeros and ones of binary computer logic. Yet the common strategy of running current pulses through wires to induce magnetic fields to rotate the elements is flawed. The fringe fields that are generated may interfere with neighboring elements.
Argonne's team says that a change in voltage—not current—should be used to flip the memory element's spins, since this process doesn't produce any magnetic fringe fields. Voltage-controlled spin rotation is a potentially valuable strategy for the design of magnetic RAM devices. Argonne's researchers, though, aren't stopping with the memory element.
All-spintronic computers could eliminate the need for parallel processing and multiprocessor servers. Computing could be accelerated and customized with reprogrammable logic devices. A magnetic CPU's architecture could be reconfigured in real time for whatever task is at hand. A combination of reprogrammable magnetic processors and essentially unlimited magnetic RAM, along with highly dense magnetic materials with superior heat-dissipation ability, could result in pocket-sized machines that surpass the performance of some of today's most advanced computers.
Of course, Argonne's concepts are still waiting for proof-of-concept tests. Many major manufacturers, though, already are investigating magnetic RAM technology, and they're keeping their eyes on magnetic CPUs for the future. With the magnetic storage industry currently accounting for $150 billion a year, this seems like a wise investment.
For more information, point your browser to Argonne's web site at www.techtransfer.anl.gov.