Researchers at Seagate have now demonstrated that heat-assisted magnetic recording can be done reliably. They used a magnetic-writing head outfitted with near-field optics to write data to a hard disk coated with stable recording media. Today in the journal Nature Photonics, the researchers describe their system and report recording data at densities of 250 gigabits per square inch.

This density only matches that of the hard disks found in today's laptops. But that's not the point, say researchers. "This is a tour de force in the science and engineering of this technology," says Schlesinger.

The Seagate prototype is made almost entirely out of components that are found in today's hard drives, says Ed Gage, executive director of research on recording systems at the company. The prototype uses a different recording medium than do today's hard disks, but it can be laid down using the same processes already employed in the industry. Likewise, the writing head is the same as those already being made by the company, except for the addition of the optics.

The company now plans to bring the recording density up. "The experimental system needs additional engineering work," says William Challener, another researcher on the Seagate project. The size of light achieved in the prototype was about 70 nanometers; other researchers have demonstrated 20 nanometers in the lab, and the company hopes to match this. There also remains some work to be done on integrating an electronic control system for the laser into a hard drive.

Meanwhile, others are working on a second technology for boosting magnetic storage. This approach, called bit patterning, involves increasing the density and stability of magnetic bits by creating patterned arrays of very regularly shaped, nanoscale magnetic grains.

"These approaches each have very different strengths and weaknesses," says Barry Schechtman, executive director emeritus of the Information Storage Industry Consortium. "But there's a strong consensus that five to ten years out, only one won't be enough. We'll need a combination of bit patterning and heat-assisted magnetic recording."