Superefficient memory for future computers uses T-rays

The necktie structure acts as an antenna to capture the T rays and change the state of the spin. [Image: Schlauderer et al. - 10.1038 / s41586-019-1174-7]

Data recording with T-rays

A team from Germany, Russia and the Netherlands was able to reverse the magnetic polarization of a material in the smallest time scales ever obtained, at a minimal energy cost.

When you take into account that 3% of all electricity produced in the world is already spent on data centers - the so-called cloud - any gain in the storage efficiency of each bit of information can make a big difference to the economy and the environment environment. This is one of the great objectives of the field of spintronics .

Computers store data in bits that alternate between two basic states, interpreted as zeros and ones. Remagnetizing the bit, making it change state, requires a lot of energy - and it's not as fast as we'd like.

The team developed a route for the ultrafast spinning of the spin in a material called thulium orthoferrite, one of the elements of the rare earth family.

The great news is that the switching is done by T rays, or terahertz radiation.

Picoseconds

The new technique was possible because there seems to be a special connection between the spin states and the electrical component of a T-ray pulse. This allowed us to remagnetize the memory bits faster and more efficiently than is possible using pulses of magnetic field.

The terahertz pulses last in the range of the picoseconds, which corresponds to a cycle of light oscillation, that is, it is much faster than any current technology.

The switching of each spin was completed in only 3 picoseconds and almost no dissipation of energy - the team ensures that the dissipation of energy is at the minimum level of loss imposed by the fundamental laws of thermodynamics.

The next step is to move from proof of concept to components closer to end use.

Bibliography:  Temporal and spectral fingerprints of ultrafast all-coherent spin switching S. Schlauderer, C. Lange, S. Baierl, T. Ebnet, CP Schmid, DC Valovcin, AK Zvezdin, AV Kimel, RV Mikhaylovskiy, R. Huber  Nature Vol. : 569, pages 383-387  DOI: 101038 / s41586-019-1174-7