11.02.2019 change 11.02.2019

Physicists discover new methods of recording information

Fig. press materials/University of Bialystok Fig. press materials/University of Bialystok

A new method of recording information that will allow to use light more efficiently to record data in digital memory has been presented by an international group of physicists led by a researcher from the University of Bialystok.

The results of research conducted by an international team of physicists led by Dr. Andrzej Stupakiewicz from the Faculty of Physics of the University of Bialystok have been published in the prestigious journal Nature Communications (https://doi.org/10.1038/s41467-019-08458-w).

The article presents a new concept of selective ultrafast magnetic cell recording in cobalt-doped garnet layer. The recording is made using ultra-short laser pulses with a combination of optical parameters, such as polarization, wavelength and light intensity. According to Dr. Stupakiewicz, quoted in the press release sent by the University of Bialystok, this opens the way to "photomagnetic 3D recording", which would allow even more efficiently use light to record information in digital memory.

The results are a continuation of research published in 2017 in Nature, about which we have already written. According to researchers, their method of ultrafast cold information recording remains the fastest and most efficient method of recording with light.

"Now we have verified another scientific hypothesis based on original ideas developed in Bialystok" - says Dr. Stupakiewicz, quoted in the press release. "This time, we have developed a mechanism for the selective activation of cobalt ion cells with different crystallographic symmetry, thus demonstrating how to more efficiently switch magnetization during recording" - the scientist adds.

The authors of the publication explain that the recording mechanism is associated with an extremely effective resonance optical excitation of certain electron transitions in the garnet layer. Physicists estimate that even one photon can switch magnetization of cobalt cells with a volume of only 28 nm3 (cubic nanometers). For comparison: in the most capacious terabyte HDDs currently available, the recorded bit cell has a volume of about 4000 nm3.

Thanks to the use of "3D recording" a specific area of the layer can be coded by a beam of light with a defined combination of parameters, using the optical telecommunication band. This means that in the future photomagnetic recording technology, it will be possible to use miniature optic fibre lasers for both recording and transfer of recorded digital information using the existing optical transmission infrastructure.

The publication is a result of international cooperation of scientists from the Department of Physics of Magnetism of the University of Bialystok with physicists from Nijmegen (the Netherlands) and Moscow (Russia). One of its authors is Dr. Krzysztof Szerenos, a graduate of the Faculty of Physics, University of Bialystok, currently a postdoctoral researcher at the University of Nijmegen.

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