Ever wished you had a super-reliable computer that used less power and could instantly start-up and be ready for use? Researchers from Cornell University are working on a new technology that could lead to just such a breakthrough.
A team from the Ithaca, New York-based institution said that modern computer memory technology requires electric currents in order to encode data. This, they explain, is a major inhibitor to enhanced reliability and shrinkability in computers. However, if data could be encoded without current, it solves these issues while also reducing power consumption.
Postdoctoral associate John Heron and his colleagues are in the process of developing a computer which would encode data using an electric field applied across an insulator. As they work towards that goal, they have announced the successful completion of a room-temperature magnetoelectric memory device equivalent to one computer bit.
This breakthrough, which the researchers said “exhibits the holy grail of next-generation nonvolatile memory: magnetic switchability, in two steps, with nothing but an electric field,” is described in a new paper published Wednesday in the journal Nature.
“The advantage here is low energy consumption,” Heron explained in a statement. “It requires a low voltage, without current, to switch it. Devices that use currents consume more energy and dissipate a significant amount of that energy in the form of heat. That is what’s heating up your computer and draining your batteries.”
This device was created out of a compound known as bismuth ferrite, which is frequently used by researchers because it is both magnetic and ferroelectric. In other words, it has its own permanent local magnetic field, is also constantly electrically polarized, and can have its polarization changed simply by applying an electric field. Typically, ferroic materials possess either one trail or the other, but bismuth ferrite is one of the rare materials that have both.
This combination makes bismuth ferrite a “multiferroic” material, and as researchers at the University of California, Berkeley first demonstrated 11 years ago, the compound can be grown as extremely thin films which can exhibit the same enhanced properties as other, bulkier materials, illustrating its desirability for use in next-gen technological development.
“Because it’s multiferroic, bismuth ferrite can be used for nonvolatile memory devices with relatively simple geometries,” Cornell University officials explained. “The best part is it works at room temperature; other scientists… have demonstrated similar results with competing materials, but at unimaginably cold temperatures, like 4 Kelvin (-452 Fahrenheit).”
“A key breakthrough by this team was theorizing, and experimentally realizing, the kinetics of the switching in the bismuth ferrite device,” they added. “They found that the switching happens in two distinct steps. One-step switching wouldn’t have worked, and for that reason theorists had previously thought what they have achieved was impossible.. but since the switching occurs in two steps, bismuth ferrite is technologically relevant.”
The resulting multiferroic device appears to require significantly less energy than its primary competitor, a phenomenon known as spin transfer torque that takes advantage of different physics for magnetic switching. The spin transfer torque technique is currently seeing limited commercial use, but there is still work to do on Cornell’s new device.
For instance, the developers were only able to create a single unit, and billions will be required for actual computer memory arrays. The multiferroic device also needs to become more durable, they noted. For now, however, they said, that “proving the concept is a major leap in the right direction.”