How do magnetic waves behave in antiferromagnets and how do they spread? What role does the “domain wall” play in the process? And what does this mean for the future of data storage?These questions are the focus of recent publications in the journal Physical review letter From an international research team led by Konstanz physicist Dr. Davide Bossini. The team is working on antiferromagnetic magnetic phenomena that can be triggered by ultrafast (femtosecond) laser pulses and can add new capabilities to materials for energy efficient and ultrafast data storage applications. I will report.
Storage capacity demand is growing faster than available infrastructure
The proliferation of use of big data technologies and cloud-based data services means that global demand for data storage is constantly expanding. At the same time, the technologies currently available will never be able to keep up. “In the meantime, if we can’t develop new and more efficient technologies for data storage and processing, it’s estimated that the growing demand can only be met for a limited period of about 10 years,” the university said. Said Dr. Davide Bossini, a physicist at the University of Tokyo. Lead author of Konstanz and research.
Continuing to build today’s state-of-the-art data centers is not enough to prevent a data crisis. Future technologies will need to be faster and more energy efficient than traditional mass data storage based on magnetic hard disks. Antiferromagnets, a class of materials, are promising candidates for the development of next-generation information technologies.
We are all familiar with household magnets made of iron and other ferromagnets. These materials, like the small needles on a compass, contain atoms that are all magnetically oriented in the same direction, resulting in magnetic polarization (magnetization) that affects the surrounding environment. In contrast, antiferromagnets have atoms with alternating magnetic moments that cancel each other out. Therefore, antiferromagnets do not have a net magnetization and do not have a magnetic effect on the surrounding environment.
However, internally, these antiferromagnets, which are abundant in nature, are divided into many small regions called domains, and the magnetic moments in the opposite directions are aligned in various directions. Domains are separated from each other by a migration area called a “domain wall.” “These transition regions are well known for antiferromagnets, but until now little was known about the effect of domain wall on the magnetic properties of antiferromagnets, especially in very short time increments. “Dr. Bossini says.
Femtosecond magnetic phenomenon
In the current article, researchers explain what happens when an anti-ferrometric material (more specifically, a crystal of nickel oxide) is exposed to an ultrafast (femtosecond) laser pulse. The femtosecond scale is so short that even light can travel very short distances during this period. In one trillionth of a second (1 femtosecond), light travels only 0.3 micrometers. This corresponds to the diameter of a small bacterium.
An international team of researchers have shown that domain walls play an active role in the dynamic properties of nickel oxide in antiferromagnets. Experiments have shown that electromagnetic waves of different frequencies can be induced, amplified, and even coupled to each other between different domains, but only in the presence of domain walls. “Our observations show that the ubiquitous presence of antiferromagnetic domain walls can potentially be used to give these materials new functionality on an ultra-fast scale,” Bossini explains. increase.
An important step towards more efficient data storage
The ability to combine different electromagnetic waves across the domain wall highlights the possibility of actively controlling the propagation of magnetic waves in time and space, as well as the energy transfer between individual waves on the femtosecond scale. This is a prerequisite for using these materials for ultra-fast storage and processing of data.
These antiferromagnetic-based data storage technologies are orders of magnitude faster and more energy efficient than today’s. You can also store and process large amounts of data. Since the material has no net magnetization, it is less vulnerable to malfunction and external manipulation. “Therefore, future technologies based on antiferromagnets will meet all the requirements of next-generation data storage technologies and may also meet the growing demand for data storage and processing power,” Bossini said. Concludes.
Reference: D. Bossini, M. Pancaldi, L. Soumah, M. Basini, F. Mertens, M. Cinchetti, T. Satoh, O. “Coherent Magnon Mode Ultrafast Amplification and Nonlinear Magnetic Elastic Coupling in Antiferromagnets” by Gomonay, S. Bonetti, August 9, 2021 Physical review letter..
DOI: 10.1103 / PhysRevLett.127.077202
- Study on the role of domain wall in the dynamic magnetic properties of antiferromagnets on an ultrafast time scale
- In the presence of domain walls, with the help of laser pulses, electromagnetic waves of different frequencies can be induced, amplified and bonded to each other between different domains of nickel oxide in the material.
- Active control of electromagnetic wave propagation in time and space, and energy transfer between individual waves in antiferromagnets, are promising steps towards the use of materials in future data storage and data technologies.
- Funding: German Research Foundation (DFG), European Science and Technology Cooperation (COST), Knut and Alice Warenberg Foundation, Swedish Research Council (VR), European Research Council (ERC), National Science Foundation (NSF).
Magnetic Phenomena Discovery Paves Way to Faster and More Efficient Data Storage Source link Magnetic Phenomena Discovery Paves Way to Faster and More Efficient Data Storage