Imagine a laptop that never gets hot, a phone that holds its charge for days, or a computer memory chip designed to permanently retain data, even when the power goes out. This is the possibility sitting inside a remarkable family of materials that a team of researchers from the University of Ottawa and the Massachusetts Institute of Technology (MIT) has spent years trying to understand and they just published a comprehensive roadmap of the field to date.
Magnetic topological materials sit at the crossroads of magnetism and topology in modern physics. Topology is the mathematical study of shapes that cannot be continuously deformed into one another. In these materials, that idea protects the flow of electrons in a way that normal materials simply cannot.
"Magnetic topological materials offer a unique platform where magnetism and quantum physics work together in ways we are only beginning to fully understand," explains Hang Chi , Canada Research Chair in Quantum Electronic Devices and Circuits and Assistant Professor at uOttawa's Department of Physics. "This review brings together the field's most significant advances and gives researchers a shared foundation to build on."
The sweeping review of over twenty years of research from across the globe now provides the scientific community with a common starting point.
Professor Chi and his co-authors, Dr Peng Chen and Professor Jagadeesh S. Moodera of MIT, walked through the four main families of these materials, explaining the interesting quantum effects they produce, and laid out where the biggest opportunities for real-world technology lie. One of the most striking of those effects is called the "quantum anomalous Hall effect", a state where electrical current flows along the edges of a material with virtually no energy loss in absence of external magnetic field. Achieving that reliably and efficiently is a milestone the field has been chasing for years.
"What excites us most is how these materials can enable electrical current or voltage-induced magnetization switching with efficiencies that exceed conventional metals by orders of magnitude," says Professor Chi. "That translates directly into devices that are faster, smaller, and dramatically more energy-efficient than what we have today."
The one problem scientists still need to solve
Currently, these effects only show up when the materials are cooled to temperatures fractions of a degree above absolute zero. Getting these materials to work at room temperature is the field's biggest challenge. The study points to three concrete pathways forward: using powerful computers and artificial intelligence to rapidly screen thousands of candidate materials, engineering new combinations of materials in thin layered structures, and discovering entirely new families of magnetic topological materials that have not been found yet.
"We are not there yet, but we now have a much clearer roadmap," adds Professor Chi. "By combining advances in material synthesis, computational screening, and machine learning, we believe room-temperature magnetic topological devices are within reach."
The way we build computers and electronic devices is approaching its physical limits. Chips are getting so densely packed that heat has become one of the biggest obstacles to making them faster. The materials described in this review do not just offer incremental improvement, they represent a fundamentally different approach to moving and storing information, one that could make devices cooler, faster, and far more energy efficient. Beyond computing, these materials are already showing early promise in artificial intelligence hardware, physical circuits that process information the way the human brain does, rather than the way a traditional calculator operates. In a world where AI data centres are consuming electricity at a staggering and growing rate, that matters enormously.
The review, titled " Progress and prospects of magnetic topological materials for spintronic applications " is published in Newton (A Cell Press journal). Authorship: Peng Chen, Hang Chi, and Jagadeesh S. Moodera.
