In a leap forward for condensed-matter physics and digital technology, researchers at the University of Nottingham report the discovery of a new magnetic phase, dubbed “altermagnetism.”
The discovery unites the best characteristics of established magnetic types, promising transformative advancements in digital devices and spintronic applications.
“Altermagnets consist of magnetic moments that point antiparallel to their neighbors. However, each part of the crystal hosting these tiny moments is rotated with respect to its neighbors,” study co-author and professor of physics and astronomy at the University of Nottingham, Dr. Peter Wadley, said in a statement. “This is like antiferromagnetism with a twist! But this subtle difference has huge ramifications.”
For decades, magnetism has underpinned the foundation of modern technology, from hard drives to quantum research. The two conventional categories, ferromagnetism and antiferromagnetism, have distinct advantages but also inherent limitations.
Ferromagnets, known for their internal magnetization, are the backbone of commercial memory devices but suffer from scalability and inefficiencies due to their net magnetic moment. Conversely, antiferromagnets provide speed and robustness but lack the spintronic properties necessary for broader technological integration.
This newly discovered third class of magnetism, altermagnetism, bridges these two paradigms, offering the advantages of both without their drawbacks.
In a study recently published in Nature, scientists demonstrated the ability to visualize and control altermagnetic states within manganese telluride (MnTe) at nanoscale resolution.
Unlike ferromagnets, altermagnets exhibit no net magnetization, making them highly energy-efficient. Yet they retain strong spin-current effects akin to ferromagnets, enabling their application in high-performance memory systems.
Researchers used advanced X-ray magnetic circular dichroism (XMCD) and linear dichroism (XMLD) to reveal intricate altermagnetic textures, including nanoscale vortices and domain walls.
The study showed that these textures could be manipulated using thermal cycling and magnetic fields, a key breakthrough for creating functional devices.
The implications of this discovery could be profound. Altermagnetism provides a pathway to highly scalable, energy-efficient devices.
With no net magnetization, altermagnetic materials are inherently compatible with superconductors and other sensitive phases. This compatibility makes them ideal for cutting-edge quantum and neuromorphic technologies.
Unlike traditional magnetic materials, which are susceptible to external perturbations, altermagnets’ vanishing net magnetization allows them to perform reliably in extreme environments, a significant advantage for applications requiring durability and precision.
The researchers employed molecular beam epitaxy to grow MnTe films and used a combination of XMCD and XMLD photoemission electron microscopy to map and control altermagnetic states.
By doing so, they demonstrated that the spin textures in MnTe could be manipulated at scales ranging from nanometers to micrometers. This breakthrough in imaging allowed the team to produce detailed maps of the magnetic order vector and to manipulate specific spin configurations, such as single-domain states and vortex-antivortex pairs.
This discovery could revolutionize the way we approach digital and neuromorphic spintronic devices. By integrating the advantages of ferromagnetic and antiferromagnetic behaviors, altermagnets offer unprecedented flexibility for designing spintronic systems.
The ability to control magnetic states at the nanoscale opens the door to various practical applications. Altermagnets can support memory devices that are smaller, faster, and more energy-efficient than their ferromagnetic counterparts.
Their unique properties also make them compatible with superconducting phases, paving the way for advancements in quantum computing. Additionally, their high spatial and temporal scalability makes them well-suited for neuromorphic computing, a field focused on creating systems that mimic the human brain.
Beyond immediate applications, altermagnetism offers a new research frontier. It introduces the possibility of exploring interactions with topological phases, unconventional spin-polarization phenomena, and advanced electronic materials.
The compatibility of altermagnetic states with a variety of conduction types—from insulators to metals—signals its broad utility across scientific disciplines. Researchers are particularly excited about its potential in designing digital devices that are energy-efficient and resistant to external magnetic-field disturbances.
“Our experimental work has provided a bridge between theoretical concepts and real-life realization, which hopefully illuminates a path to developing altermagnetic materials for practical applications,” lead study author and Senior research fellow at the University of Nottingham, Dr. Oliver Amin, explained.
The findings from this study also highlight the importance of patterning and field cooling for shaping altermagnetic textures. By applying external magnetic fields during thermal cycling, the team demonstrated the ability to form large single-domain states within MnTe, an essential feature for creating stable, high-performing devices.
The scalability of these techniques suggests that altermagnetic materials could be used in a wide range of applications, from nanoscale components to macroscale systems.
Spintronics, which exploits the intrinsic spin of electrons for data processing and storage, stands to benefit immensely from altermagnetism. Current spintronic devices rely heavily on ferromagnetic materials for their ability to read and write data.
Altermagnets, with their robust spin-current effects and zero net magnetization, represent a step forward in creating devices that are not only more compact but also immune to the inefficiencies of traditional approaches.
As researchers continue to explore this new magnetic phase, the future of altermagnetism looks promising. The ability to precisely manipulate magnetic states and create scalable, energy-efficient systems has the potential to transform multiple fields, from consumer electronics to advanced computing. Altermagnets could become the foundation of next-generation devices, delivering more innovative, faster, and more reliable technologies.
Ultimately, the discovery of altermagnetism signifies a paradigm shift in our understanding of magnetism and its applications.
By overcoming the limitations of traditional ferromagnetic and antiferromagnetic systems, altermagnets offer a unique solution that aligns with the growing demands of modern technology.
With further exploration and development, altermagnetism could become a cornerstone of innovation, revolutionizing industries and reshaping the future of digital devices.
Tim McMillan is a retired law enforcement executive, investigative reporter and co-founder of The Debrief. His writing typically focuses on defense, national security, the Intelligence Community and topics related to psychology. You can follow Tim on Twitter: @LtTimMcMillan. Tim can be reached by email: tim@thedebrief.org or through encrypted email: LtTimMcMillan@protonmail.com