Compact disks could make a comeback: scientists have developed a new type of optical memory

The breakthrough may herald the dawn of an era of optical storage with "ultra-high density," yet extensive research still lies ahead.

Scientists from the University of Chicago and Argonne National Laboratory (USA) have developed a new type of optical memory that stores data by transferring light from rare earth element atomsRare earth elements are a group of 17 chemical elements (15 lanthanides plus scandium and yttrium) characterized by unique magnetic and optical properties, making them useful in cutting-edge technologies. to quantum defectsQuantum defects are atomic irregularities in a material that can interact with quantum particles (such as light), allowing data to be preserved at the subatomic level.. The study's results were published in the journal Physical Review Research.

Conventional CDs and DVDs have an intrinsic limitation—no single bit of information can be smaller than the wavelength of the laser reading it. The scientific team proposed a method to circumvent this physical constraint.

The researchers initially created a physical model and calculated all requirements for the experimental sample. They modeled the theoretical material with rare earth atoms that absorb and re-emit light. The models demonstrated how closely positioned quantum defects could capture and retain the reflected light.

Using wavelength Wavelength multiplexing is a technology that enables simultaneous transmission of different signals over a single channel using various wavelengths. multiplexing, each emitter operates at its own frequency. This allows for significantly more data to be written in the same area of the storage medium.

The key discovery is that the absorption of energy at a narrow wavelength alters the spin stateThe spin state is a quantum characteristic of particles that describes their intrinsic angular momentum, or spin. of the defect. The altered state is nearly impossible to revert, making such defects reliable for long-term data storage.

Scientists regard this discovery as "an important first step," though commercial products are still a long way off. Researchers need to determine how long data can be retained in the excited state. While the scientists promise "ultra-high density" recording, they have yet to provide specific predictions regarding the capacity of the new disks.

Source: Techspot