SCIENTIFIC EDUCATIONAL CENTER science idea

Electronic devices are getting smaller every year — the elements they consist of are also decreasing. Physicists from the Kurchatov Institute synthesized submonolayer magnetic films-ordered structures with a thickness of one atom, but significantly more sparse than a monolayer of matter. These objects represent a fundamentally new class of two-dimensional magnetic materials and can become the basis for creating new electronic devices: quantum computers, ultra-compact transistors, information storage and transmission systems.

In recent years, the paradigm of information technology development has undergone fundamental changes. Aggressive miniaturization of microchip elements leads to the fact that, due to fundamental physical limitations, the principles underlying the operation of devices stop working at the turn of a few nanometers. From a physical point of view, the main problems of scaling nanoelectronics are related to energy release. Spintronics, which uses spin as a data carrier, allows us to solve this problem. In the last few years, the creation of two-dimensional magnets has provided a breakthrough in the element base of spintronics. Two-dimensional magnets are magnetic materials with a thickness of several monolayers, that is, layers with a thickness of one atom. These systems are extremely sensitive to external influences — electric and magnetic fields, pressure, temperature — which is important for creating components of quantum computers, logic and memory devices based on new principles.

"Two-dimensional magnetism as a separate field of research appeared only about five years ago. The rapid development of two-dimensional ferromagnetism made it possible to create magnetic materials with a thickness up to a monolayer. It would seem that the physical limit of miniaturization of such materials has been reached, but we have shown in our work that this is not the case, " says the head of the project under the grant of the Russian Academy of Sciences, Professor Vyacheslav Storchak, Doctor of Physical and Mathematical Sciences, head of the laboratory of new elements of nanoelectronics at the Kurchatov Institute.

The idea of creating submonolayer magnets-one atom thick, but much more sparse than in the case of a monolayer — appeared in the course of work in which it was possible to synthesize magnetic graphene. As is known, graphene exhibits a number of unique properties, in particular electrical and mechanical. However, it is non-magnetic, which limits the possibilities of its use in spintronics. By integrating the carbon lattice of graphene with the atoms of the rare earth element europium, physicists from the Kurchatov Institute (Moscow) managed to introduce magnetic properties into the system. The observation of the anomalous Hall effect at high carrier mobility allowed us to conclude that spin-polarized electrons occur.

Having studied magnetic graphene at the European Center for Synchrotron Research (ESRF, Grenoble) together with French colleagues, physicists determined the magnetic structure of the monolayer system. In this material, there is only one europium atom per six carbon atoms of graphene. This allowed the researchers to suggest that it is possible to create two-dimensional magnets with a low surface density of magnetic atoms. The idea was implemented for silicon, the basic material of modern electronics. The researchers of the Kurchatov Institute synthesized the structures of europium on the purified silicon surface using the methods of molecular beam epitaxy. The resulting submonolayer structures exhibit magnetic properties similar to those of magnetic graphene. The two-dimensional nature of ferromagnetism in submonolayer systems integrated with a silicon platform makes it possible to control the magnetic properties of the system with small magnetic fields.

"We have obtained ordered superstructures of a new class of two-dimensional magnetic materials. This class of magnets can form the basis of breakthrough technologies for storing and transmitting information. We hope that spintronics based on two-dimensional magnets will lead to the creation of fundamentally new, ultra-compact transistors, as well as computer memory elements. We plan to expand the class of submonolayer magnets by using various magnetic atoms and semiconductor platforms. It seems to us that spintronics based on two-dimensional magnets can be very promising, " Vyacheslav Storchak sums up.

The results of the work supported by a grant from the Russian Science Foundation (RPF) are published in the journal ACS Nano
Photo: On the left — the structure of magnetic graphene (top and side views), on the right-the scheme of measuring the magnetic structure of EuC6 on a synchrotron by X-ray magnetic circular dichroism © Vyacheslav Storchak

A source: scientificrussia.ru, sci-dig.ru