Proceedings

EPJ B Highlight - Precise electron spin control yields faster memory storage

Top panel shows a 2D view of spin dynamics for bulk nickel..

New ultra-fast laser method aims to improve control over the electron’s degree of freedom, called spins, could enhance memory storage devices

Data storage devices are not improving as fast as scientists would like. Faster and more compact memory storage devices will become a reality when physicists gain precise control of the spins of electrons. They typically rely on ultra-short lasers to control spins. However, improvement of storage devices via spin control requires first to develop ways of controlling the forces acting on these electronic spins. In a recent study published in EPJ B, John Kay Dewhurst and colleagues, have developed a new theory to predict the complex dynamics of spin procession once a material is subjected to ultra-short laser pulses. The advantage of this approach, which takes into account the effect of internal spin rotation forces, is that it is predictive.

In this study, the authors study the effect of firing an ultra-short laser pulse - below 100 femtoseconds - on the internal electron spin rotation in bulk cobalt, nickel and combinations of these metals with platinum. These metals are typically used in spintronics devices - electronic devices which exploit the extra degree of freedom of electron spins. Unlike previous studies where the magnetic moment was forced to be aligned with the internal fields that generate it, in this study the authors use a fully non-aligned approach to create a theoretical description. As a result, spin rotation’s contributions to the spin dynamics are taken into account. This makes the method applicable to a far broader set of magnetic materials than previous methods.

The authors find that internal spin rotation forces only contribute significantly to spin dynamics when the variation in different directions of the magnetic energy - or magnetic anisotropy energy - is small. This is the case with materials which are highly symmetric such as bulk metals with a cubic structure. When such magnetic anisotropy energy is large, the spin rotation effect is too small to cause any significant precession of spins below 100 femtoseconds. Further, the spin-dynamics caused by the internal spin-rotation is slow compared to other spin phenomenon, such as the inter site spin transfer between electrons and the spin-flips, mediated by spin-orbit.

J. K. Dewhurst, A. Sanna, S. Sharma (2018), Effect of exchange-correlation spin-torque on spin dynamics, European Physical Journal B 91:218, DOI: 10.1140/epjb/e2018-90146-1

This was our first experience of publishing with EPJ Web of Conferences. We contacted the publisher in the middle of September, just one month prior to the Conference, but everything went through smoothly. We have had published MNPS Proceedings with different publishers in the past, and would like to tell that the EPJ Web of Conferences team was probably the best, very quick, helpful and interactive. Typically, we were getting responses from EPJ Web of Conferences team within less than an hour and have had help at every production stage.
We are very thankful to Solange Guenot, Web of Conferences Publishing Editor, and Isabelle Houlbert, Web of Conferences Production Editor, for their support. These ladies are top-level professionals, who made a great contribution to the success of this issue. We are fully satisfied with the publication of the Conference Proceedings and are looking forward to further cooperation. The publication was very fast, easy and of high quality. My colleagues and I strongly recommend EPJ Web of Conferences to anyone, who is interested in quick high-quality publication of conference proceedings.

On behalf of the Organizing and Program Committees and Editorial Team of MNPS-2019, Dr. Alexey B. Nadykto, Moscow State Technological University “STANKIN”, Moscow, Russia. EPJ Web of Conferences vol. 224 (2019)

ISSN: 2100-014X (Electronic Edition)

© EDP Sciences