A magnetless spin-memory device

Could allow for miniaturization of a memory bit down to a single nanoparticle
August 16, 2013

Optical microscopy picture of magnetless spin-memory device (credit: The Hebrew University of Jerusalem)

Scientists at Hebrew University of Jerusalem and Weizmann Institute of Science have developed a simple magnetization technology that eliminates the need for permanent magnets in memory devices and allows for fabricating inexpensive, silicon-compatible, high-density, universal memory-on-chip devices.

Current memory devices have significant drawbacks: dynamic RAM memory has to be refreshed periodically, static RAM data is lost when the power is off, flash memory lacks speed, and all are are reaching limits of miniaturization.

In an paper published in Nature Communications, open access), the scientists describe a new technique, called magnetless spin memory (MSM), which drives a current through chiral material (an abundantly available organic molecule) and selectively transfers electrons to magnetize nanomagnetic layers or nanoparticles.

With this technique, the researchers showed it is possible to create a magnetic-based memory device that does not require a permanent magnet, and which could allow for miniaturization of a memory bit down to a single nanoparticle.

Magnetless spin-memory technology has the potential to overcome the limitations of other magnetic-based memory technologies and could make it possible to create inexpensive, high-density universal memory-on-chip devices that require much less power than existing technologies. Compatible with integrated circuit manufacturing techniques, it could allow for inexpensive, high-density, universal memory-on-chip production, the researchers say.

Schematic drawing of the magnetless spin memory device. Gold contacts are represented in yellow, the thin ferromagnetic nickle is in transparent purple, the aluminum oxide layer above the chiral molecules is in red, the silicon oxide is in light blue, and the silicon is in dark blue. Reading or writing is performed by driving the current between the two gold contacts. When current flows through the device, the electrons are polarized by the chiral molecules, which then transfer their polarization to the nickel and magnetize it. Reading is achieved by driving a small current and measuring the change in the resistance. The resistance correlates with the magnetization of the nickel. (Oren Ben Dor et al./Nature Communications)

According to Hebrew University’s Prof. Yossi Paltiel, “Now that proof-of-concept devices have been designed and tested, magnetless spin memory has the potential to become the basis of a whole new generation of faster, smaller and less expensive memory technologies.”

The technology transfer companies of the Hebrew University (Yissum) and the Weizmann Institute of Science (Yeda) are working to license its use and raising funds for further development and commercialization.