Data Storage Technique Supporting Energy Efficient Servers

Researchers have a data storage technique that can cut the energy required to write data in half and make it easier to create complex server architectures.
Whether it’s sending grandparents a few photos of children, streaming a movie or music, or browsing the web for hours, the amount of data our society is generating is constantly increasing. But this is expensive as storing data consumes a huge amount of energy.Assuming that data volumes will continue to grow in the future, the corresponding power consumption will also increase by several orders of magnitude. For example, IT energy consumption is projected to rise to ten petawatt hours, or ten trillion kilowatt-hours, by 2030. This will be equivalent to about half of the electricity generated worldwide.

But what can be done to reduce the amount of energy required to run servers? Data is usually stored in the storage layer by magnetization. To write or delete data, electric currents are passed through ferromagnetic multilayer structures where the flowing electrons generate an effective magnetic field. The magnetization in the storage layer “senses” this magnetic field and changes its direction accordingly. However, each electron can only be used once.

An important step in energy-efficient storage is the creation of a ferromagnetic storage layer that includes a heavy metal such as platinum. When current flows through heavy metal, electrons switch back and forth between the heavy metal and ferromagnetic layers.

A team of researchers from Johannes Gutenberg University in Mainz (JGU), working in collaboration with researchers from Forschungszentrum Jülich, have now found a way to double the efficiency of this storage process. “Instead of using plain silicon as a substrate, as is common practice, we use a piezoelectric crystal,” explained Mariia Filianina, a PhD student at the School of Materials Science in Mainz and a PhD at the Max Planck Center. “We attach a layer of heavy metals and a ferromagnetic layer to this.” If an electric field is then applied to the piezoelectric crystal, it creates mechanical deformation in the crystal. This, in turn, enhances the magnetic switching efficiency of the storage layer, which is the storage element. The degree of efficiency improvement is determined by the system and the electric field strength. “We can directly measure the change in efficiency and therefore adjust the corresponding field strength on the fly,” Filianina said.

In other words, the efficiency of the magnetic switching process can be directly controlled by adjusting the strength of the electric field to which the piezoelectric crystal is subjected.

 data storage 2.0

This not only leads to a significant reduction in power consumption but also makes it possible to use complex architectures for storing information. The researchers speculate that if an electric field is applied only to a small area of ​​the piezoelectric crystal, the switching efficiency will only improve at that location. If they now adjust the system so that the electron spins can only switch when the strain in the piezoelectric crystal increases, they can change magnetization locally. “Using this method, we can easily implement tiered memory and complex server architecture,” said Maria Filianina.