UC San Diego Engineers Use Shaped Laser Light to Advance Magnetic Data Storage

Engineers at the University of California San Diego have demonstrated an experimental method that utilizes specially structured light beams to alter the magnetic properties of storage media, offering a potential foundation for next-generation data storage hardware. Detailed in a study published in Nature Communications and reported by TechXplore (https://techxplore.com/news/2026-09-material-magnetic-properties.html), the technique replaces traditional external magnetic fields with ultrafast laser pulses to switch magnetic states within microscopic material domains. The researchers estimate that this optical switching methodology could execute write operations more than 1,000 times faster than conventional magnetic-field approaches while lowering power consumption and increasing bit density.

Standard digital storage devices, including hard disk drives and related magnetic recording systems, store binary data by flipping tiny magnetic regions between opposing states to represent ones and zeros. Achieving these state changes traditionally requires applying localized external magnetic fields, an energy-intensive process that constrains writing speeds and physical recording density. Optical switching offers an alternative because light can deliver concentrated energy almost instantaneously to a narrowly defined region, enabling faster and more efficient control of individual bits.

However, integrating optical switching into commercial memory devices has historically been hampered by material limitations. Previous laboratory trials demonstrated that light-induced magnetic state changes could occur only within ultrathin magnetic films comprising no more than three material layers. Furthermore, those earlier methodologies depended strictly on specific light polarization states to induce bit flips. Attempts to increase the material's thickness past three layers consistently suppressed the optical switching effect, placing a strict upper bound on the medium's volume and limiting its ability to retain stored data reliably over long periods.

To overcome these constraints, the UC San Diego team focused on re-engineering the light source itself. By shaping the laser beam and shrinking its footprint by tens of orders of magnitude compared to beams used in previous approaches, the researchers successfully induced optical switching in a thicker magnetic structure consisting of nine alternating layers of platinum and cobalt. The modified approach also eliminated the strict reliance on light polarization. "We've optically engineered the light to change the physics that's happening in the material at the micro- and nanoscale," said Muhammad Waleed Khalid, the study's first author and a Ph.D. student in electrical and computer engineering at UC San Diego.

The technique works by concentrating light energy onto a microscopic target area and subjecting it to a rapid succession of ultrafast pulses. The initial pulses heat a tiny localized region sufficiently to create a reversed magnetic area. Subsequent laser pulses then gradually expand that switched region until it stabilizes. Senior study author Abdoulaye Ndao, a professor of electrical and computer engineering at the UC San Diego Jacobs School of Engineering, noted that beam dimensions directly dictate hardware performance. "The smaller the size of the beam, the smaller and denser the optical memory," Ndao said.

The project brought together specialists across optics and magnetic materials. Ndao's optics group collaborated with Eric Fullerton, a professor of electrical and computer engineering and chemical and nano engineering, who holds an endowed chair at UC San Diego's Center for Memory and Recording Research. "Instead of designing a new material to enable optical switching, we redesigned the light itself and showed new properties that were not previously thought to be possible," Ndao said. Because the findings departed from existing assumptions, Khalid noted that the team spent extensive time replicating and validating their experiments to substantiate their work to the optics community.

Commercial deployment of the light-driven storage technique remains several steps away. The current experimental setup relies on a specialized ultrafast laser that cannot yet be readily integrated into computer chips. Moving forward, the research team is pursuing two main avenues: identifying alternative magnetic material compositions that react to simpler, chip-integrable lasers, and designing novel optical structures that can confine light down to a few hundred nanometers.