Researchers from Tohoku University and the Massachusetts Institute of Technology (MIT) have revealed a representative of the effect of anomalous materials (Reveals the anomaly of non-collinear antiferromagnets) at play when electricity is applied to a new class of magnetic materials called antiferromagnets noncollinear.
Their findings were published in the journal Nature Materials on August 3, 2023. Magnets are important in today’s society. In recent years, non-collinear antiferromagnets have attracted a lot of attention because of their interesting properties that are different from ordinary magnets. In a traditional collinear magnet, the magnetic moment is linear.
However, in those that are not collinear, time forms a critical part between them. Scientists describe these non-collinear structures as a single structure, the octupole period, which has been shown to be important in detecting phenomena.
The researchers found that the octupole phase shows a negative response to the electric current, that is, it turns in the opposite direction to the general magnet system. The disorder was found to arise from the interaction between the electron and the unique chiral structure of the antiferromagnet.
“The physical properties of the non-collinear antiferromagnet give it wide potential for applications in computer hardware,” said Ju-Young Yoon, lead author of the study and a doctoral student at the University. from Tohoku.
“Our research provides the basis for spintronic devices such as memories and oscillators.” Spintronics is an interdisciplinary field that uses spin electrons to manipulate electricity and magnetism, which can make our electronic devices faster, smaller and more efficient.
Around the year 2000, alternating current magnetization was demo
nstrated in collinear ferromagnets, commonly called magnets. This research has led to the recent commercialization of high performance memory.
Spin-transfer torque magnetoresistive random-access memory (STT-MRAM) is expected to play an important role in the future low-carbon society.
Nonlinear antiferromagnets have been the focus of the spintronic community. Despite its very weak magnetization, its chiral structure makes ferromagnetic materials such as the strong Hall effect. Such phenomena are known to be described by the octupole moment, which one can compare to the magnetization of ferromagnets.
Although the magnetization of the current has been improved significantly in the last two decades, this is not the case for the octupole dynamics, requiring structural analysis.
For this, the researchers investigated the octupole phase response in antiferromagnetic manganese-tin (Mn3Sn). By applying a magnetic field to the electric field, they compared the magnetization of ferromagnetic Cobalt-Iron-Boron (CoFeB).
Although the direction of magnetization rotation is the same between the field and the current terms, that of the octupole moment is different for a noncollinear antiferromagnet.
Through further analysis, they revealed that the individual magnetic moments rotate in the same direction for both systems, but the combined effect causes the octupole moment to move in the opposite direction due to the special chiral rotation of antiferromagnetic noncollinear.
“The electrical control of magnetic objects is very important in spintronics. We have provided important information for the control of non-collinear ferromagnets, which is very different from the electrical control of collinear ferromagnets,” said Professor Luqiao Liu. from MIT.
Professor Shunsuke Fukami of Tohoku University reiterated this and added that “the commercialization of STT-MRAM has been achieved through a strong understanding of the relationship between magnetization and precipitation.
In this respect, this work should provide a solid foundation for development of work. devices with non-collinear antiferromagnets.”
Source: Tohoku University.
