Brief

UC San Diego engineers switch magnetic memory with reshaped laser light

The new optical‑switching method works on a nine‑layer platinum‑cobalt stack, overcoming thickness limits of earlier experiments.

By Felo News Desk · Published Fri, 02 Oct 2026 08:14:24 GMT

ScienceDaily reported that engineers at the University of California, San Diego have demonstrated a way to write magnetic data using a specially shaped beam of light from an ultrafast laser, eliminating the need for an external magnetic field. The technique, described in a paper published in Nature Communications, succeeded on a stack of nine alternating layers of platinum and cobalt, far thicker than the three‑layer limit of previous optical‑switching experiments.

Traditional magnetic storage writes bits by applying a magnetic field to flip tiny magnetic regions that represent 1s and 0s. That process consumes significant energy and limits write speed. Light, by contrast, can deliver energy in femtosecond bursts and focus it on a nanometre‑scale spot, offering a potential speed advantage of more than a thousand times, according to the researchers.

Senior author Abdoulaye Ndao, a professor in UC San Diego’s Department of Electrical and Computer Engineering, explained that earlier work showed the optical effect vanished when the magnetic stack exceeded three layers, restricting long‑term memory stability. By reshaping and shrinking the laser beam, the team overcame both the thickness constraint and the need for a specific light polarization, which had previously limited the method.

PhD students Muhammad Waleed Khalid and Koffi Sadzi set up the optical system and adjusted the beam profile for the experiments. Their results showed reliable switching of magnetic states across the nine‑layer stack without changing the light’s polarization, demonstrating that beam engineering can replace material‑specific restrictions.

The researchers estimate that optical switching could enable data‑writing speeds far beyond current magnetic‑field‑based approaches, potentially leading to faster, more compact storage devices. However, the study remains at the laboratory stage, and further work will be needed to integrate the method into commercial memory architectures.

Key facts

UC San Diego engineers used a reshaped ultrafast laser beam to switch magnetic bits without an external magnetic field. (scitechdaily.com)
The optical switching succeeded on a nine‑layer stack of platinum and cobalt, extending beyond the previous three‑layer limit. (scitechdaily.com)
Researchers claim the method could be more than 1,000 times faster than magnetic‑field‑based writing. (scitechdaily.com)
The work was published in Nature Communications and involved PhD students Muhammad Waleed Khalid and Koffi Sadzi. (scitechdaily.com)
The new approach eliminates the need for a specific light polarization, a restriction in earlier experiments. (scitechdaily.com)