The apparent inner calm of quantum materials

Transitions between different phases of matter are part of our day-to-day lives: when water freezes, for example, it passes from liquid to solid state. Some of these transitions may be of a different kind, resulting from so-called topological excitations that force all the particles to act in unison. Researchers from the University of Geneva (UNIGE) and the CEA,CNRS and UGA have been studying BACOVO -- a one-dimensional quantum material unknown to the general public -- in collaboration with scientists from the neutronic centers ILL and PSI. They have discovered in this material a novel topological phase transition, governed not by a single type of topological excitation, but by two different ones. In addition, they were able to choose which of the two sets would dominate the other. You can read all about their research in the journal Nature Physics.