revolution in optical storage media?
The volume of information generated annually is growing: for example, humanity is now creating about 147 zettabytes of data per yearand by 2025 this figure could grow to 181 zettabytes. The need for new solutions in information storage is becoming more acute, so storage manufacturers are constantly developing more capacious systems.
But perhaps it is worth not only looking for new technologies, but also improving existing ones. New research The University of Chicago and Argonne National Laboratory have shown that long-forgotten CDs and DVDs can find a new life. The use of quantum defects and rare earth elements makes it possible to repeatedly increase the data density on optical media. It is possible that they will be able to compete with modern storage technologies. To be fair, it should be said that there are more questions to this work than answers. Details are under the cut.
Limitations of optical discs
To understand what is behind this scientific breakthrough, let's remember the limits of CD and DVD media. Their main disadvantage is the limited data density caused by the diffraction limit of light. The minimum size of the recording area is limited by the light wavelength itself. CD uses 780 nm laser and distance 1.6 µm. In DVD discs, where the recording density is higher, the laser wavelength is 635 nm, and the recording pitch is reduced to 0.74 microns. Therefore, a standard CD can only store about 700 MB of data, while a DVD can store up to 4.7 GB on a single-layer disc. It is impossible to go beyond this limit using traditional methods; here we have hit the ceiling of the technology itself.
Overcoming limitations and a potential solution to the durability problem
Perhaps from the thorns you can go to the stars. Recent Research showedthat the integration of rare earth elements into optical storage media and the creation of “quantum defects” could radically change the situation. Quantum defects are tiny anomalies in the crystal lattice structure of a material that are capable of absorbing and trapping light waves of specific wavelengths. Researchers offered use wavelength multiplexing to record information, which allows you to store several bits of data on the same disk area. The principle is that different sections of the media can be tuned to specific wavelengths, which are subsequently read out with greater information density.
This method allows you to increase the amount of data recorded on the media with a significant reduction in the size of the latter. In theory, it is possible to create a new kind of multilayer optical disc that can accommodate 1,000 times more information than traditional CD/DVD.
The experiments were carried out using magnesium oxide (MgO) with the addition of rare earth atoms, which can absorb and re-emit light at very specific wavelengths. When interacting with quantum defects, such “emitters” stably retain information in the spin state, which makes the system promising for long-term data storage.
But this study needs further verification. The team of scientists has not yet determined how durable such storage media will be under real-life operating conditions. It's important to note that many quantum technologies require cryogenic coolingand this is impossible and unprofitable for mass implementation. It is, of course, possible to imagine a laser disk drive operating at cryogenic temperatures, but in reality such a system will only work in laboratory conditions and will not be commercially applicable.
Researchers continue to study the stability of such systems and the efficiency of the energy transfer process between emitters and quantum defects, using a combination of classical physical methods of recording information and quantum modeling.
The new type of optical disks have a high chance of working in archival data storage. Such systems, subject to the development of commercially viable technology, will be purchased by government agencies, research centers and large corporations that need to store huge amounts of data for decades. Unlike hard drives and SSDs, which are subject to wear and tear and simply fail over time, drives based on quantum effects are more stable and suitable for long-term storage of information.
Real world application: data archiving and storage
New technology developed by scientists looks promising, but remains many unresolved issues. It remains to be determined how long quantum defects can keep data in a stable state—a point the scientists did not highlight at the presentation of their work.
But there are questions here too, because the study does not detail the final capacity of such disks and the ability to write them multiple times, similar to modern rewritable CD-RWs and DVD-RWs. Most likely, the new technology will require special devices for writing and reading. How they will work and what their price is, at least approximately, is unknown.
All of this could affect the attractiveness of the new method to corporations. If the technology comes into use, it will be for storing “cold” data. It is difficult to imagine arrays of drives for high-capacity laser disks used to work with “hot” information in corporate data centers. And of course, this is not a household technology; at home, the likelihood of using it tends to zero.
The prospects for new work by scientists may seem distant, but understanding how quantum defects work has become an important step towards further progress in the field of data storage. Well, whether a revolution will happen or not, only time will tell.
In general, there is a lot to discuss here, so if you want, tell us your opinion in the comments.
