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As is known, in the microelectronic industry, the primary carrier of information is an electron. Spin-orbitronics (miniature electronics) are based on the transmission of spin magnetic moment, which requires much less energy than when transferring an electric charge.[1]
2021: Ultra-fast way of data management is open
On December 24, 2021, MIPT scientists reported that an ultra-fast way to manage data has been discovered.
It has been reported that an increase in the amount of information stored requires the development of other methods and technologies for energy-efficient and fast data processing and storage. The interaction of elementary magnetic moments of electrons (spins) with the lattice plays a decisive role in the process of recording magnetic bits. Researchers from the Netherlands, together with scientists from Russia, discovered a mechanism for turning on and off spin-lattice interaction, controlled by ultra-short pulses of terahertz frequency light. The results are published in the scientific article "The connection of antiferromagnetic spins with the lattice, controlled by terahertz light" in the world scientific journal Science.
Antiferromagnetic magnons can be used as data carriers in magnetic material and replace traditional electronics elements. Unlike electrons, such spin waves practically do not interact with the lattice and therefore can propagate to microscopic distances without scattering. At the same time, weak interaction makes it difficult to control the propagation of spin waves. A study conducted by a group of scientists from the Netherlands and Russia showed that interaction can be controlled using light.
 | Intuitively, one could believe that the interaction of spins with the lattice is a property of a particular material and can hardly be changed. We have shown that interaction can be controlled with light. This means that we have discovered a way to control the propagation of spin waves and thus have taken an important step towards another technology of data processing in the future. said Evgeny Mashkovich, first author of the article |  |
| | Optimization of spin-lattice interaction in quantum materials is one of the main tasks when creating magnetic storage systems. It determines both the speed and energy efficiency of recording magnetic bits. We found that the terahertz pulse resonantly interacts with magnon in cobalt (CoF2) difluoride antiferromagnetics. The same approach to controlling spin-lattice communication using terahertz light should work in other magnetic materials. said Anatoly Zvezdin, professor, leading researcher at the Laboratory of Physics of Magnetic Heterostructures and Spintronics, MIPT, chief researcher at the Institute of General Physics named after A.M. Prokhorov RAS | |
The researchers believe that this technology will help solve the problems of magnetic storage of data and ensure ultra-fast recording at minimum energy costs.
The work was attended by scientists from the Institute of Molecules and Materials (IMM) of Radbaud University (Netherlands), the Institute of General Physics named after A.M. Prokhorov RAS, the Center for Photonics and Two-Dimensional Materials of the Moscow Institute of Physics, Institute of Physics II, Cologne University (Germany), MIREA - Russian University of Technology and O.
2020: FEFU develops an approach to create miniature electronics of the future
On August 24, 2020, it became known that scientists at the School of Natural Sciences of the Far Eastern Federal University (SHEN FEFU), together with colleagues from Russia, South Korea and Australia, proposed a method for managing the spin-electronic properties and functionality of thin-film magnetic nanosystems. The discovery is important for creating the next generation of miniature electronics (spin-orbitronics) and computer memory. The article is published in NPG Asia Materials. Scientists from the laboratory of film technologies SHEN FEFU propose to control the functionality of a magnetic nanosystem, built on the principle of a sandwich, through the surface roughness of a magnetic film sandwiched between a layer of heavy metal and a coating layer.
As explained, by varying the amplitude of roughness on the lower and upper surfaces (interfaces) of the magnetic film in the range of less than a nanometer, which is comparable to the size of atoms, the researchers were able to maximize the useful spin-electron effects important for the future electronics. To do this, it has been found that on the lower and upper interface of the magnetic film, the roughness must repeat each other.
The workability of the approach was first demonstrated on the example of a magnetic system consisting of a palladium (Pd) layer with a thickness in the range of 0 to 12 nanometers (nm), coated with a platinum layer with a thickness of 2 nm and a ferromagnetic (alloy CoFeSiB) with a thickness of 1.5 nm. The multilayer structure was covered with a layer of magnesium oxide (MgO), tantalum (Ta) or ruthenium (Ru) - various materials - "covers" allow expanding the ability to control the magnetic properties of the nanosystem.
| | In modern electronics, transistor sizes decrease all the time. At the same time, as of August 2020, the general development trend is aimed at obtaining atomic-smooth defective surfaces. However, it would be a big mistake to strive for ideal interfaces, because many physical effects lie outside the atomic ordering and perfectly flat surfaces. With a decrease in the functional elements of electronics, the role of surface roughness increases very much. Thanks largely to the development of analytical equipment, we have just begun to deeply penetrate the nature of the detected phenomena and understand the role of roughness and atomic mixing on interfaces. The main message of our study is that atomic roughness can be used for the benefit of implementing spin-orbitron devices with improved properties. | |
The scientist said that over the past five years, the field of physics, spin-orbitronics has been actively developing in the world. She studies not just the spin of an electron (the intrinsic moment of the electron pulse is a quantum property that is not associated with the movement (movement or rotation) of an electron as a whole), but a spin-orbital interaction. Such interaction occurs between an electron orbiting around an atomic nucleus and creating a magnetic field, and its own magnetic moment, which is due to the spin of the electron.
The advantage of spin orbitronics is that the functionality of the devices being created (for example, magnetic memory) is provided directly through the control of spin-orbital interaction in their constituent nanomaterials, for example, in heavy metals.
Heavy metals of the platinum group (Ru, Rh, Pd, Os, Ir, Pt) have a sufficiently strong spin-orbital interaction. If one of these metals is brought into contact with a thin thickness of several atomic layers, a magnetic film (for example, Co, Ni, Fe, Py), it is possible to radically change the electronic and magnetic properties of the system.
| | Firstly, magnetization can be controlled by obtaining nanosystems magnetized perpendicular to the plane of the film - this is done in modern hard drives and developing next-generation media to increase density, storages information increase write/read speed data and number of rewriting cycles. Secondly, a strong spin-orbital interaction in a heavy metal leads to the "deformation" of the electron orbitals of the atoms of the magnetic material (film), as a result of which spin effects arise, such as magnetic attenuation and the Dzyaloshinsky-Moriy interface interaction that appears at the border of the heavy metal and the magnetic layer covering it. This antisymmetric interaction leads to the transformation of the ferromagnetic order and the appearance of non-trivial spin textures, such as skyrmions and skirmioniums. Such spin textures have enormous potential for the electronics of the future, playing the role of non-volatile media. For example, based on them, it is possible to make computer memory components that will work without magnetic heads, and the bits in them will be switched by current pulses due to the "coup" of electron spins. Such devices will operate at bit rates up to several km/s under the influence of only electric current and accommodate an order of magnitude more data. supplemented by Alexander Samardak, author of the research idea, doctor of physical and mathematical sciences, vice-rector of FEFU for scientific work | |
For the experiment by molecular beam epitaxy, the researchers grew a series of palladium films with a single crystal structure, Fig. 1 (a). Scientists have found that the rough surface of Pd films can be described by sinusoidal function. By varying the thickness of the films Pd in the range from 0 to 12.6 nm, they were able to control the amplitude and roughness period in the range from 0 to 2 nm and from 0 to 50 nm, respectively. After that, thin films of platinum and magnetic alloy Pt (2 nm )/ CoFeSiB (1.5 nm) were applied to the surface of palladium by magnetron spraying in vacuum and coated with various materials (magnesium oxide, tantalum, ruthenium), Fig.1 (b). The "cover" material strongly influenced magnetic anisotropy, while the effect on the Dzialoshinsky-Moriy interaction was not so significant. At the same time, the applied layers Pt and CoFeSiB repeated the morphology of the surface Pd.
As a result, the researchers found that by not changing the composition of the magnetic system, but only varying the surface roughness in the sub-nanometer range by changing the thickness of the Pd layer, its functional properties can be changed. For example, the value of the Dzialoshinsky-Moriy interaction increased by 2.5 times with a Pd layer thickness of 10 nm. It was with this thickness that the roughness of the lower and upper interfaces of the magnetic film was correlated as much as possible.
According to Alexander Samardak, the study took about four years, it took another year to publish an article in the prestigious journal of Nature. Reviewers for a long time could not believe in the ability to control spin-orbital properties by modulating roughness. During the correspondence, the authors managed to convince the reviewers and defend their point of view. In August 2020, samples are being prepared together with foreign partners to study the effect of interface roughness on the spin Hall effect and the effect of transmitting spin-orbital torque of the pulse, which will make it possible to closely approach the implementation of memory cells, the magnetic moment of which is switched only by electric current.
The work was carried out as part of State Task No. 0657-2020-0013 of the Ministry of Education and Science of Russia "Multifunctional magnetic nanostructures for spintronics and biomedicine: synthesis, structural, magnetic, magneto-optical and transport properties."
As of August 2020, FEFU scientists are conducting fundamental research and practical developments in the priority areas of the Strategy for the Scientific and Technological Development of the Russian Federation, including such areas as the types of materials that are necessary for the transition to future technologies.
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