UChicago PME Scientists Create Ultra-Dense Data Storage
A new computer memory storage method from the University of Chicago Pritzker School of Molecular Engineering (UChicago PME) could revolutionise microelectronics. Scientists have developed a way to store massive amounts of data in crystals' small defects, where atoms should be. Since one cubic millimetre of material may hold gigabytes of data, this revolutionary technology may increase storage density.
Traditionally, “on” and “off” items have been associated with information storage. This rule applies to 19th-century punch card looms and current telephones. Modern laptops express binary ones and zeroes with transistors that flip between low and high voltage. A “zero” on a compact disc means no change, but a “one” can go from a little indentation “pit” to a flat “land,” or vice versa. Traditional storage device capacity was limited by physical component size.
The UChicago PME team created memory cells utilising atomic-scale crystal defects to overcome this restriction. Assistant Professor Tian Zhong says, “each memory cell is a single missing atom a single defect.”
As Zhong says, “Now you can pack terabytes of bits within a small cube of material that’s only a millimetre in size,” miniaturisation allows amazing density. The researchers found that the millimetre cube could store at least a billion atom-based classical memories. This incredible density promises to revolutionise data storage and elevate typical computing memory.
UChicago PME's interdisciplinary research ethic is reflected in this invention, which skilfully employs quantum techniques to change classical, non-quantum computing. However, succeeded to integrate solid-state physics applied to radiation dosimetry with a quantum-savvy research team.
This uncommon combination was discovered by Zhong's postdoctoral researcher Leonardo França, the first author of the study. While quantum system researchers are needed, conventional non-volatile memory store capacity must be increased, he said. This relationship between quantum and optical data storage underpins work. They created “a new type of microelectronic device, a quantum-inspired technology,” Zhong said.
This work addresses the critical need to expand the storage capacity of traditional non-volatile memory that protect data during power outages.
França's PhD studies at the University of São Paulo in Brazil inspired this groundbreaking work. Radiation dosimeters, used in particle accelerators and hospitals to track radiation exposure, were his first interest. França studied materials that absorb radiation and store it.
He became interested when he realised that optical means, such as shining a light on the substance, might control and access this stored information. França explained: “Electrons and holes are released from the crystal when it absorbs enough energy.” Additionally, defects catch charges. Optical data recovery is possible by freeing trapped electrons. After realising memory storage's huge potential, França successfully integrated his non-quantum results into Professor Zhong's quantum laboratory to lead to this multidisciplinary breakthrough in classical memory storage.
The scientists developed the new memory storage technology using an oxide crystal and lanthanide ions. They used Praseodymium and a Yttrium oxide crystal to take use of rare earths' strong and varied optical properties, but the method can be applied to many materials. It is well known that rare earths have electronic transitions that allow optical control of laser excitation wavelengths from ultraviolet to near-infrared regimes.
Unlike X-ray or gamma dosimeters, this new storage device is activated by a simpler ultraviolet laser. Lasers induce rare earth ions to release electrons. Flaws in the oxide crystal structure, such as oxygen-free gaps, trap these electrons. “It’s impossible to find crystals in nature or artificial crystals that don’t have defects,” França remarked, emphasising their prevalence. He continued, “So what we are doing is we are taking advantage of these defects,” outlining their inventive approach.
The UChicago PME team found a novel use for classical memory, even though crystal defects are often used in quantum research to create “qubits” in stretched diamond or spinel. Their method allowed them to precisely charge and not charge these defects. By ingeniously identifying a charged gap as a “one” and an uncharged gap as a “zero,” they turned the crystal into a powerful memory storage device on a scale never before seen in traditional computing.
The UN has declared 2025 the International Year of Quantum Science and Technology to commemorate a century of quantum engineering and science. This work proves that “crystal defect memory” can be used for data storage in the future, circumventing size constraints that have plagued storage devices. This invention shows how cutting-edge science benefits everyone.
