A team of researchers from the University of Ottawa and the Massachusetts Institute of Technology has published what they describe as a comprehensive roadmap of magnetic topological materials, a family of substances that could one day make laptops run without overheating, extend phone battery life for days, and allow computer memory chips to hold data permanently without power.
The review, published in the journal Newton, draws on more than 20 years of research from across the globe and walks through the four main families of these materials, according to a report by Phys.org. The goal is to give the broader scientific community a common foundation to work from.
Magnetic topological materials sit at the crossroads of two areas of modern physics: magnetism and topology. Topology is the mathematical study of shapes that cannot be continuously deformed into one another. In these materials, that principle protects the flow of electrons in ways that normal materials cannot match.
"Magnetic topological materials offer a unique platform where magnetism and quantum physics work together in ways we are only beginning to fully understand," said Hang Chi, Canada Research Chair in Quantum Electronic Devices and Circuits and Assistant Professor at the University of Ottawa's Department of Physics. "This review brings together the field's most significant advances and gives researchers a shared foundation to build on."
Chi co-authored the review with Dr. Peng Chen and Professor Jagadeesh S. Moodera of MIT. Together, they mapped out the most promising quantum effects these materials produce and identified where the biggest opportunities for practical technology exist.
One of the most striking effects described in the review is called the quantum anomalous Hall effect, a state where electrical current flows along the edges of a material with virtually no energy loss, and without any external magnetic field. Achieving that effect reliably has been a major goal for researchers in the field 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," Chi said. "That translates directly into devices that are faster, smaller, and dramatically more energy-efficient than what we have today."
The catch is that these effects currently only appear when the materials are cooled to temperatures just fractions of a degree above absolute zero, which is roughly negative 459 degrees Fahrenheit. Bringing these materials up to room temperature is the field's central unsolved problem, and the review lays out three concrete paths researchers are pursuing to get there.
The first path involves using powerful computers and artificial intelligence to rapidly screen thousands of candidate materials, searching for ones that might exhibit these properties at higher temperatures. The second involves engineering entirely new combinations of materials in thin layered structures, which can produce effects not seen in any of the individual components alone. The third pathway, though not fully detailed in the available source material, rounds out the roadmap the team has drawn for the field.
The review represents a consolidation of research from institutions around the world, and the authors frame it as a starting point rather than a conclusion. By surveying what has been accomplished over two decades, Chi and his colleagues are positioning the field to move faster toward devices that could eventually reach commercial use.
The journal Newton published the roadmap as part of its coverage of emerging materials science.