Smaller, faster and cheaper memory chips without permanent magnets

Memory devices including disk drives, flash drives and RAM are an essential components of computers, phones, electronic appliances and cars but current memory devices have 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 existing memory technologies are challenged when it comes to miniaturisation.

Consequently, memory devices are a bottleneck limiting performance. In order to achieve a substantial improvement in computation speed, scientists are developing smaller and denser memory devices that operate with high speed and low power consumption.

One solution is so-called magnetless spin memory (MSM) developed by Prof Yossi Paltiel and research student Oren Ben-Dor at the Hebrew University of Jerusalem’s Harvey M. Krueger Family Center for Nanoscience and Nanotechnology, together with researchers from the Weizmann Institute of Science. MSM  is claimed to eliminate the need for permanent magnets in memory devices.

A paper describing their work - A chiral-based magnetic memory device without a permanent magnet - is published in Nature Communications. Contributors include Shira Yochelis at Hebrew University of Jerusalem; plus Shinto P Mathew and Ron Naaman at the Weizmann Institute of Science.

The research deals with the flow properties of electron charge carriers in memory devices. According to quantum mechanics, in addition to their electrical charge, electrons also have a degree of internal freedom called spin, which gives them their magnetic properties.

According to the university, the new MSM technique drives a current through a chiral material (a material whose molecules have no rotational or reflectional symmetry) and selectively transfers electrons to magnetise 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 the miniaturisation of memory bits down to a single nanoparticle.

Compatible with integrated circuit manufacturing techniques, it could allow for inexpensive, high density universal memory-on-chip production.

In a statement, Prof Paltiel said, ‘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.’

Yissum and Yeda, the technology transfer companies of Hebrew University and the Weizmann Institute of Science respectively, are working to promote the realisation of this technology by licensing its use and raising funds for further development and commercialisation.