"Detecting topological orders in quantum matter" Seminar by Frank Pollmann (MPI-PKS Dresden)

Seminar

Theory of Quantum Matter Unit would like to invite you to a seminar presented by Dr. Frank Pollmann, Group leader of Topology and Correlations in Condensed Matter Group at MPI-PKS Dresden.  

• Title: "Detecting topological orders in quantum matter"
• Speaker: Dr. Frank Pollmann (MPI-PKS Dresden)
• Date / Time: 25th Nov (Tue) / 14:00-15:00
• Venue: C016, Lab 1 

Detecting topological orders in quantum matter

Frank Pollmann, MPI-PKS Dresden

Matter occurs in various phases that are usually characterized in terms of symmetry breaking. A major discovery in the 1980s were the quantum Hall effects which exhibit a new kind of “topological” order. This order represents a class of exotic phases which cannot be described by spontaneous symmetry breaking. The lack of symmetry breaking order parameters makes it difficult to characterize these phases. In this talk, I will show that numerical investigations of a many-body wavefunction can yield a remarkably complete characterization of different types of topological orders. A central tool is the ground state entanglement which encodes many of the essential features.  First, I will show how characteristic properties of the topological excitations in spin liquids and fractional quantum Hall states can be extracted directly from the ground state wave functions. Second, I will consider symmetry protected topological phases in one-dimensional systems for which a complete classification can be derived from the entanglement.