A way to speed up computer memory by 1,000 times has been found

Engineers at the University of California San Diego have learned to control the magnetic states of a material by changing the shape and focus of a laser beam. The approach could become the basis for faster and denser data recording. The study was published in the journal Nature Communications.

In magnetic storage devices, information is stored as small regions with different magnetization directions. These states correspond to digital zeros and ones. Typically, an external magnetic field is used to switch them, but researchers are seeking ways to perform the same operation using light pulses.

The authors worked with multilayer structures made of platinum and cobalt. Instead of changing the material's composition, they focused on the properties of light: the polarization distribution within the beam and its focusing. This allowed them to control localized heating and the effect of radiation on magnetization.

The team demonstrated that a specially shaped beam can trigger different switching modes. In one case, the development of the magnetic domain depends on the direction of the light's polarization rotation, while in the other, the magnetization reversal occurs without such dependence. No external magnetic field was required for this.

In the experiments, a sequence of ultrashort pulses created a small region with opposite magnetization and gradually expanded it. The scientists also managed to achieve switching in a thicker structure than previous experiments of this type had allowed. This is important for developing materials capable of reliably retaining recorded information.

According to the researchers' estimates, optical switching can potentially operate more than a thousand times faster than approaches based on external magnetic fields. However, this is an estimate of the technology's capabilities: the team did not create a finished storage device with such acceleration.

Engineering challenges remain before practical application. The ultrafast laser used is still difficult to integrate into a computer chip. The authors plan to reduce the area of effect to a few hundred nanometers and to search for combinations of materials and light sources more suitable for compact electronics.