Topological order: New phases of matter with fascinating properties
Dr. Frank Pollmann (Max-Planck-Institut für Physik komplexer Systeme, Dresden)

Matter occurs in various phases with different properties. For example, certain solids become magnetic when cooled to sufficiently low temperatures, and others become superconductors. Usually these phases are characterized in terms of symmetry breaking. A major discovery in the 1980s was the quantum Hall effect which forms a new kind of order called “topological” order that cannot be understood in terms of symmetry breaking. One of the characterizing features of topological order is the presence of non-trivial exchange statistics of the excitations meaning that they are neither bosons nor fermions. These so-called anyonic excitations might make topologically ordered systems ideal building blocks of fault-tolerant quantum computers that will be able to solve difficult problems which are impossible to solve using present-day (“classical”) computers.