A Particle Accelerator Accidentally Created a Nanoscale Bat-Signal

Holy magnetic reversal, Batman!

Jan 12 2015, 7:10pm

The Bat-Signal in question. Image: PSI/Nature Communications.

The image of Jesus Christ has graced pieces of toast, dental X-rays, and a Cheeto, while apparitions of the Virgin Mary have shown up on everything from pebbles to pizza pans. But once you get down to the nanoscale, it turns out that Batman is the king of coincidental iconography. At least that's what researchers based out of the Paul Scherrer Institute (PSI) discovered after the Bat Signal showed up while they were testing a new concept for ultra-efficient data storage.

Illustration of the magnetic structures generated by laser beams. Image: PSI/Nature Communications.

As much as I'd love to enshrine this image as a herald of Batman's obvious divinity, it would be no more reputable a claim than worshipping the Jesus Cheeto. But the research behind the image is worth touting, not to mention it would be right up Lucius Fox's technophile alley.

In a paper published today in Nature Communications, the PSI team laid out a novel approach to engineering smaller, faster, and more efficient data storage. Of course, optimizing the performance of hard drives is a major goal across many disciplines, and countless research teams are chipping away at the problem from multiple angles. But this study approached the problem a bit differently, by using lasers to inscribe information on microstructures, rather than using the traditional magnetic head method.

Data is written and stored on hard drives magnetically, and it is usually recorded and read by a head that flows over the drive like a needle on a record player. But in the PSI study, mind-bogglingly short laser pulses were used to imprint information on an ultra-sensitive microstructure. Made up of magnetic squares with areas of about 25 square micrometers each, these structures reacted to the pulses by magnetically reversing their polarities.

The nanoscale Bat Signal was created because the individual squares that make up the microstructure didn't uniformly switch polarities when hit with laser light. The black bat shape represents where the magnetic substructures were reversed, while the white background retained its original polarity.

"Using light for magnetic switching clearly works," said Frithjof Nolting, who led the study, in a PSI statement. "But why exactly it does is still the subject of debate in the research community."

The Bat Signal is far from the only pattern that was produced in the study, though it's certainly the most eye-catching. But the broader upshot is that lasers could be used to magnetize extremely small and precise microstructures, allowing for much more efficient hard drives.

"This could be the way to store even more data on even smaller hard drives one day," said co-author Loïc Le Guyader, in the PSI statement.

Nolting (left) and Le Guyader (right) on the x-ray microscope at the Swiss Light Source. Image: Paul Scherrer Institute/M. Fischer.

Aside from the Batman cameo, the most memorable part of the study was the incredibly high resolution used to image these magnetic reversals. With input from specialists from the Netherlands, Germany, and Japan, the PSI team was able to produce snapshots at a rate of 70 billion per second. That's 600 million times the rate of a motion picture, and it speaks volumes about the capabilities of the PSI's synchrotron, the Swiss Light Source (SLS). As impressive as the SLS's shutter speed is, however, it doesn't beat out the insane 100 billion frames per second rate achieved by a Washington University team a month back.

Then again, Washington University didn't get a Bat Signal out of its study, and that achievement should really be the gold standard for nanoscale research from here on out. Along those lines, perhaps the next image resolved by the SLS will reveal the ominous grin of the Joker. After all, every tiny, magnetically rendered superhero emblem deserves a premium rogue's gallery.