5D 'Superman memory crystal' heralds unlimited lifetime data storage

Data written to a glass “memory crystal” could remain intact for a million years, according to scientists from the UK and the Netherlands who have demonstrated the technology for the first time. The data-storage technique uses a laser to alter the optical properties of fused quartz at the nanoscale. The researchers say it has the potential to store a staggering 360 terabytes of data (equivalent to 75,000 DVDs) on a standard-sized disc.

Longevity and capacity are the key factors to consider in terms of data storage, but existing options are limited. “At the moment, companies have to back up their archives every five to ten years because hard-drive memory has a relatively short lifespan,” explainsJingyu Zhang of the University of Southampton, UK, who led the team that demonstrated the new technique. Optical storage media such as DVDs are more stable, but with standard single-layer discs maxing out at 4.7 GB of data, they are an unwieldy option for vast digital archives.

Scientists have been pursuing the idea of glass as a medium for mass data storage since 1996, when it was first suggested that data could be written optically into transparent materials. By using a femtosecond laser to alter the physical structure of fused quartz, a “dot” with a different refractive index can be created to denote the binary digit one; zeros are indicated by the absence of a dot. Japanese electronics giant Hitachi succeeded in storing data using this method back in 2009, but Zhang’s team has taken the technology a step further, by recording information in 5D – the three dimensions of space that describe the physical location of the dot, and two additional dimensions that are encoded by the polarity and intensity of the beam that creates the dot.