In the future, ultra-fast, low-energy data storage devices could be created using 3D magnetic nano-architecture in a breakthrough that could even herald a new era in solid state storage.
Researchers at the University of Vienna have now designed the first 3D artificial magnetic materials that can operate at room temperature, potentially laying the foundation for a groundbreaking new generation of 3D storage technologies.
While it’s theoretical at this stage, researchers Sabri Koraltan and Florian Slanovc explained to Information Age that it has all the right ingredients to create a storage drive.
“That is positive and negative ‘Bits’ that can be stored on vertices and moved around, meaning they can be written,” said Slanovc.
Slanovc pointed to the various requirements that modern storage techniques must satisfy in a range of applications and where this development fits.
“On the one hand, high storage capacities are of particular importance in server and cloud storage services. There, a large information density should be stored in the smallest area/volume possible, which should be stable over years,” he said.
“Currently, modern techniques such as HAMR (heat assisted magnetic recording) or MAMR (microwave assisted magnetic recording) promise improvement of areal storage density.
“However, this density will be always limited by the lack of the third dimension.”
This shows that including a third dimension advances the potential storage density.
“Flash drives have potentially begun to use multiple planar stacks to create an artificial third dimension; however this is still limited in terms of lifetime compared to HDDs,” said Slanovc.
In this case, given the material is 3D by default, it promises more storage density than the 2D conventional techniques.
“Depending of the desired application, different techniques will be improved and optimised to be more beneficial for the user,” Slanovc explained.
Painstaking research into microparticles
Using world-leading micro-magnetic simulation software, magnum.fe, over nearly two years the researchers have been able to carry out investigations and simulations using different structures.
They eventually settled on the lattice structure that was optimised and tested in a way that would satisfy the required definitions to have unbound magnetic charges.
“Further investigations showed that these emergent particles are steerable at room temperature,” said Koraltan.
Technically, the researchers have developed the first 3D artificial spin ice lattice hosting unbound magnetic charges.
In practice, the 3D magnetic nano-network is made up of magnetic monopoles that emerge thanks to rising magnetic frustration among the nano-elements, and are stable at room temperature.
Magnetic fields do not have a point source, like the relationship between an electron and its electric field. Each magnet has two poles: south and north.
Dividing one magnetic bar in two equal parts, each of them will have one south and one north pole again.
Slanovc explained that there exist no magnetic monopoles as elementary particles.
“However, scientists were able to artificially create emergent interactions, which behave like we would expect the magnetic monopoles to behave,” he said.
Unique properties of spin ice material
Spin ices are a class of materials which can host these emergent magnetic monopoles.
“We have designed a new artificial ice lattice, where instead of magnetic bars, we have magnetic ellipsoids, and these are arranged on the same lattice as the normal water ice.
It is optimised in such a fashion, that the emergent monopoles are unbound and can freely move if external magnetic fields are applied,” he said.
The ice lattice provides the possible paths for the mobility of unbound magnetic monopoles.
In an analogy to moving an object through a labyrinth, it is now possible to move one isolated monopole in the desired direction through the lattice.
“Our lattice is stable, so we are able to move only one magnetic charge, and we envision that it can be used as a future data storage device.”
