Recent research has identified the “orbital Hall effect,” a phenomenon that has the potential to significantly improve data storage in future computing devices. This discovery, which involves the generation of electricity through the orbital motion of electrons, offers potential advances in the field of spintronics, leading to more efficient, faster and more reliable magnetic materials. Credit: SciTechDaily.com
Research suggests new approaches to enhance spintronics and paves the way for future technological advances.
In a new advance, researchers have used new techniques to identify a previously undetected physical phenomenon that can be used to improve data storage in next-generation computing devices.
Spintronic memory, used in advanced computers and satellites, uses magnetic states created by the intrinsic angular momentum of electrons to store and retrieve data. Depending on the physical movement of the electrons, the spin of the electrons generates a magnetic current. This phenomenon, known as the “spin Hall effect,” has important applications for magnetic materials across a variety of fields, from low-power electronics to fundamental quantum mechanics.
More recently, scientists have discovered that electrons can also generate electricity through a second type of motion: orbital angular momentum. This is similar to how the earth revolves around the sun. This is known as the “orbital Hall effect,” said study co-author Roland Kawakami, a professor of physics at Ohio State University.
How to observe the orbital Hall effect
The theorists predicted that by using light transition metals – materials with weak spin Hall currents – it would be easier to find that the magnetic currents generated by the orbital Hall effect flow along them. Until now, it has been difficult to detect such things directly, but the study, led by physics graduate student Igor Lyarin, was published in the journal Science. physical review lettershowed how to observe the effect.
“For decades, various Hall effects have been continuously discovered,” Kawakami says. “But the idea of these orbital flows is completely new. The difficulty is that they are mixed with the typical heavy metal spin currents, making it difficult to distinguish between them.”
Instead, Kawakami’s team demonstrated the orbital Hall effect by reflecting polarized light (in this case a laser) off various thin films of the light metal chromium and exploring the possibility of orbital angular momentum accumulation in metal atoms. . After nearly a year of careful measurements, the researchers were able to detect a clear magneto-optical signal indicating that the electrons clustered at one end of the film exhibit strong orbital Hall effect properties.
Implications for future spintronics applications
Kawakami said the success of this detection could have a major impact on future spintronics applications.
“The concept of spintronics has been around for about 25 years or so and is very good for a variety of memory applications, but now people are trying to take it even further,” he said. “Right now, one of the biggest goals in this field is to reduce energy consumption, as that is the limiting factor for improving performance.”
Reducing the total amount of energy required for future magnetic materials to work properly could not only allow for lower power consumption, higher speeds, and increased reliability, but also extend the lifetime of the technology. There is a gender. Kawakami said using orbital flow instead of spin current could save both time and money in the long run.
The researchers note that this study opens up ways to learn more about how these strange physical phenomena occur in other types of metals, and the relationship between spin and orbital Hall effects. He said he would like to continue digging deeper into the complex relationship between the two.
References: “Magneto-optical detection of orbital Hall effects in chromium,” by Igor Lyalin, Sanaz Alikhah, Marco Berritta, Peter M. Oppeneer, and Roland K. Kawakami, October 11, 2023. physical review letter.
DOI: 10.1103/PhysRevLett.131.156702
Co-authors are Sanaz Alikhah and Peter M. Oppeneer from Uppsala University, and Marco Berritta from Uppsala University and the University of Exeter. This research was supported by the National Science Foundation, the Swedish Research Council, the Swedish National Computing Infrastructure, and the K. and A. Wallenberg Foundation.
Source: scitechdaily.com
