A team of nanoscientists led by Sander Otte at Delft University of Technology in the Netherlands has just unveiled the densest method ever developed to store re-writable digital data. By scooting around individual chlorine atoms on a flat sheet of copper, the scientists could write a 1 kilobyte message at 500 terabits per square inch. That's around 100 times more info per square inch than the most efficient hard drive ever created. Otte says the method could theoretically fit every book ever written onto a flat copper sheet the size of a postage stamp.
"This density is two to three orders of magnitude beyond current hard disk or flash technology. An advance of this size is remarkable, to say the least"—so writes Steven Erwin, a theoretical physicist with the U.S. Naval Research Laboratory who was not involved in developing the new technique, in an essay accompanying the scientific paper.
Way back in 1959, renowned physicist Richard Feynman gave a famous speech at CalTech called "There's Plenty of Room at the Bottom." He spoke about the promise of writing with individual atoms, musing on how exactly you could store a fantastically large amount of data in an inconceivably small space. Today, Otte and his team took a page out of Feynman's book, and quite literally too.
Otte's team used individual atoms to encode a short section of Feynman's speech on a copper tablet about 100 nanometers wide and tall. That's so small it could fit on a Flu virus with room to spare. Otte and his colleagues then cleared the spaced and typed out a segment ofOn the Origin of Species by Charles Darwin using the same atoms.
Here's how it's done: Otte's team found that they could put chlorine atoms onto a cold grid of copper metal and get them to form into perfect squares. Think of it like a checkerboard. Any empty spot that was missing a chlorine atom would like a dark square on Otte's checkerboard. Next, the researchers found they could scoot around the chlorine atoms on this grid, sort of like a sliding block puzzle, and thus rearrange where the dark spots on the grid are. It's done with a tool called a scanning tunneling microscope, which is a bit like an ultra-thin needle that can nudge atoms up and down, left and right.
To create the data storage device, Otte starts with a copper plate that's been randomly peppered with chlorine atoms, leaving plenty of blank spaces. He then scoots around the atoms until he's formed a larger 12-by-12 grid with chunks of ordered atoms and darker blank spaces. If any of these 144 chunks has some fatal error—say the copper underneath has some elemental impurity—Otte can mark off that box as defective with a tiny 4-atom symbol in its upper left-hand corner.
The arrangement of atoms and blank spaces translates to individual bits of data. A blank space followed by a chlorine atom is a 0, while the reverse (a chlorine atom and then a blank space) is a 1. Using this method, Otte can store any digital information, be it lines from a speech or small segments of computer code.
The scientists keep their copper tablets from being jumbled by storing them at hyper-cold temperatures and isolated in a vacuum. That's technology you won't soon see on a thumb drive, "so the [practical] storage of data on an atomic scale is still some way off. But through this achievement we have certainly come a big step closer," says Otte. At -320 Fahrenheit, the research team was able to store one of their 1-kilobyte records for about two days with no errors. And rewriting one of the copper slates is as simple as just moving around the chlorine atoms to form new combinations of ones and zeroes.
There's one other downside to Otte's method. It may be a dense way to store data, but it's also heartbreakingly slow. Reading a few short sentences on one of the copper blocks takes around 1 to 2 minutes, and writing them takes 10. But Otte's team is investigating new methods they believe could speed up their writing and readout speeds by an incredible amount, up to about 1 megabit per second, about a tenth as fast as the average U.S. computer downloads data online.
source - popularmechanics.com
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