To meet the increasing demand for better and superfast computing power, researchers have developed a novel approach that uses light pulses instead of electricity to dramatically boosts computer processing speeds. The results are presented in a paper published on 15 May in Nature (1).
The new technology replaces electricity with extremely short pulses of light — with a duration of one trillionth of a second — concentrated by special antennas on top of a magnet. In addition to being super fast, the process is so efficient that it does not generate any extra heat at all.
The growing sea of digital information will require a colossal amount of energy to store and process. Computer data — binary information in the form of 1s and 0s — are encoded in magnetic hard drives using the orientation of tiny magnets, referred to as spins. However, the process is quite inefficient because the magnetic read/write head uses electrical currents, which dissipate a massive amount of energy.
As a result, data centre servers currently make up between 2 to 5 per cent of the total global electricity consumption. Thermal management has, therefore, become a major issue. In fact, many data centres are located in cooler climates or submerged underwater in an effort to dissipate heat more effectively and reduce costs. But this does not fully erase their environmental impact – data centres contribute around 0.3 per cent to global carbon emissions – which is only likely to increase.
Now, researchers may have solved the problem of achieving faster data processing speeds without the accompanying high energy cost. The team of researchers from Lancaster University developed a tiny antenna that sits on top of the magnet creates a concentrated electric field of light. The ultrashort light bursts, within the so-called terahertz spectral range (frequencies in the far infrared), are capable of switching the orientation of the magnet ― the magnetisation ― in just one trillionth of a second.
So far, the researchers have only demonstrated the ability of ultrafast light pulses to control the magnets in the laboratory. But amazingly, the temperature of the magnet did not increase since the process only needs energy from one quantum of the terahertz light or one photon per spin. Thus, the novel antenna structures enable ultrafast spin control — and therefore, superfast computing — without generating any heat.
According to the authors, the approach is highly scalable and could be used in future storage devices, like hard drives, to achieve terahertz rates – while maximising space, increasing processing speeds, and minimising energy use.
(1) Schlauderer, S. et al. Temporal and spectral fingerprints of ultrafast all-coherent spin switching. Nature (2019). DOI: 10.1038/s41586-019-1174-7