On many areas, Computer science is now at a tipping point. We have heard for quite a long time now that it will soon reach the stage where we cannot surpass the physical limits of many of the technologies we use today. A situation that had even threatened making the famous Moore’s Law obsolete. But still, every time it seems like we have reached a limit; new technologies emerge to prove us wrong. That’s the case with memory that could soon get a serious boost with Terahertz radiation which promises big speed increases while being still in its early stages.

A multinational European team (composed of Germans, Dutch and Russian scientists from the Moscow Institute of Physics and Technology (MIPT) ), published a paper in Nature Photonics where they proposed the use of terahertz radiation – commonly known as t-rays – as an entirely new way of controlling magnetization in computer memory cells. Most of us are already familiar with T-rays as they are employed in some body imaging solutions, such as the controversial full body scanners used at some airports. The claim is that if they were used when it comes to resetting computer memory cells, instead of utilizing a magnetic field (the current method), it will result in a thousand times quicker process. The end result of this would be way faster memory, with obvious computing benefits.

A technological breakthrough
The scientists reckon that advances on this front could have a big impact on all manner of technologies, including the realization of quantum computing (which itself is taking big strides forward this year, with IBM building a quantum computer that anybody can access via the cloud).

The fact is that resetting a magnetic memory cell takes time, and trying to reduce this cycle has proven very challenging. To achieve these faster speeds, the Russian-based research team proposed that electromagnetic pulses at terahertz frequencies could be used in memory switching instead of external magnetic fields.

To find out whether T-rays could be used for convenient memory states switching (storing “magnetic bits” of information), the researchers performed an experiment with thulium orthoferrite (TmFeO3). As a weak ferromagnet, it generates a magnetic field by virtue of the ordered alignment of the magnetic moments, or spins of atoms in the microcrystals (magnetic domains). In order to induce a reorientation of spins, an external magnetic field is necessary.

However, the experiment has shown that it is also possible to control magnetization directly by using terahertz radiation, which excites electronic transitions in thulium ions and alters the magnetic properties of both iron and thulium ions. Furthermore, the effect of T-rays proved to be almost ten times greater than that of the external magnetic field. In other words, the researchers have devised a fast and highly efficient remagnetization technique — a solid foundation for developing ultrafast memory.

The scientists expect their “T-ray switching” to work with other materials as well. Thulium orthoferrite, which was used in the experiment, happens to be convenient for the purposes of demonstration, but the proposed magnetization control scheme itself is applicable to many other magnetic materials.

Co-author of the research paper, Anatoly Zvezdin, said: “We have demonstrated an entirely new way of controlling magnetization, which relies on short electromagnetic pulses at terahertz frequencies. This is an important step towards terahertz electronics.”

Memory speed is often a bottleneck that we can’t wait to see disappear, and T-ray switching might be the long awaited solution we can’t wait to see working!