A quantum state of matter has appeared in a material where physicists thought it would be impossible, forcing a rethink on the conditions that govern the behaviors of electrons in certain materials.

The discovery, made by an international team of researchers, could inform advances in quantum computing, improve electronic efficiencies, and enhanced sensing and imaging.

The state, described as a topological semimetal phase, was theoretically predicted to appear at low temperatures in a material composed of cerium, ruthenium, and tin (CeRu4Sn6), before experiments verified its existence.

At extremely low temperatures, CeRu4Sn6 reaches quantum criticality, a point where a material teeters between changes in its phase, where conditions are so cold that quantum fluctuations dominate, effectively turning the material into a puddle of waves rather than a fog of particles.

The plot twist in this study is that quantum criticality can give rise to states thought to be defined by interactions between particles, such as the behavior of electrons as discrete charge carriers.

"This is a fundamental step forward," says physicist Qimiao Si, from Rice University in the US.

"Our work shows that powerful quantum effects can combine to create something entirely new, which may help shape the future of quantum science."

In physics, topology refers to the geometry of material structures. Particular topological states can protect properties of particles, unlike the way neighboring particles might jostle and disrupt each other's behavior.