Material physics work at KTH builds on Nobel laureate' discovery

Research that was recognized with the Nobel Prize in Physics this week has spawned an entirely new research area that could lead to super-fast quantum computers.

“It’s great that the prize goes toward a field that represents basic research but also is on the verge of many exciting possibilities, says Oscar Tjernberg, professor of Material Physics at KTH Royal Institute of Technology.

The three British researchers, David Thouless, Duncan Haldane and Michael Kosterlitz, have worked theoretically and mathematically, and found explanations for why matter behaves in unexpected ways.

None of them thought their work would have practical applications but their findings have proven useful in research to create new materials, such as materials that conduct electricity without resistance.

Decisively for the three laureates, their discovery was based on using topological concepts that are ordinarily part of mathematics, and applying them to physics.

The theories that they developed in the 1970s and 1980s concerned how material goes through new phases. An everyday phase transition would be when ice turns into water. The Nobel laureates’ work showed with modern topology how certain extremely thin layers of material are transformed by low temperatures.

"Their work resulted in a whole new way to think about material physics,” Tjernberg says. “That is amazingly impressive. It’s not an easy thing to break free of ingrained concepts within research.”

The research done by Thouless, Haldane and Kosterlitz set the conditions for the research that Tjernberg is involved in, namely material that only conducts electricity in a special way on the surface. Four years ago, Tjernberg’s research team was the first in the world to discover topological crystalline insulators, a new class of topological insulators.

”The Nobel Prize honorees findings are crucial for our research; we use their work as a conceptual framework,” he says.

The purpose of Tjernberg’s research is to increase understanding of topological insulators and topological phase transitions. Better understanding of these materials and how they can be manipulated opens the door for possible future applications, primarily in IT.

“It is about developing new types of components in a number of areas – mainly for new generations of electronics – and ultimately, topological quantum computers are a possibility,” he says. “But right now we are at the level of understanding.”