Light Instead of a Magnet: A Laser Could Rewrite Data a Thousand Times Faster

Today’s storage devices store data in tiny areas that switch between two states. Engineers at the University of California, San Diego, have shown that a properly modulated flash of light is sufficient to flip a magnetic bit. No magnetic field is required. For future storage systems, this could mean greater speed, density, and energy efficiency. It’s still a long way off for laptops.

Why Magnetic Storage Is Hitting a Ceiling

Magnetic storage has been operating on the same principle for decades. You switch a small area of material to one of two magnetic states, which represent 0 and 1. The data is usually written using a magnetic field. However, this requires energy and inherently determines how quickly a bit can be flipped.

How Light Comes into Play

Writing using ultrashort laser pulses has been known for some time. The pulses last femtoseconds and can reverse the direction of magnetization in thin magnetic layers. However, there was a catch. The effect only worked in extremely thin structures, up to about three layers. It disappeared in thicker materials. The thickness, in turn, determines how long the memory retains the data.

A team led by Professor Abdoulaye Ndao took a different approach. They did not search for a new material. Instead, they altered the beam itself. They reduced its size, modified its shape, and focused it in such a way as to induce different physical processes within the material. They succeeded in demonstrating optical switching in a stack of nine alternating layers of platinum and cobalt—significantly thicker than previous experiments had allowed for.

What does this mean?

• Speed: Researchers estimate that optical switching could be more than 1,000 times faster than methods using an external magnetic field.
• Density: The smaller the beam, the smaller and denser the recording can be.
• Energy: There is no need for a magnetic field, which slows down writing and consumes energy.

Why It’s Not “1,000 Times Faster SSD”

Today’s NVMe drives are based on flash memory, where data is stored as an electrical charge. This technology is different. It is based on magnetic recording and only changes the way data is written. The number 1,000 refers to the speed at which a single bit switches in a laboratory setting, not the drive’s speed as you would experience it when copying files. In real-world storage, controllers, buses, data reading, and many other factors also play a role. Therefore, it cannot be said that a drive based on this technology would be a thousand times faster than today’s drives.

When will it be available on computers?

Realistically, not for a long time yet. The biggest obstacle is the light source. The experiment uses a specialized ultrafast laser that cannot yet be easily integrated into computer chips. Before a commercial product appears, the following issues need to be resolved:

• miniaturization and low-cost production of suitable lasers,
• precise beam steering onto a vast number of bits,
• reliable data reading,
• long-term stability of the recording.

What to Take Away From This

This work is important because it shows how data storage can continue to advance as traditional technologies approach their physical limits. It is a step in basic research, not a product you’ll be able to buy anytime soon. Interestingly, the improvement did not come from a new material, but from better-designed light.