Masaki Oshikawa

---

Classification of quantum phases is one of the central problems in
statistical mechanics and condensed matter physics. Traditionally,
it had been associated to spontaneous symmetry breakings.
However, a rich variety of quantum phases without any spontaneous
symmetry breaking have been found and dubbed as topological
phases. Symmetries can still play an important role even when there
is no spontaneous symmetry breaking, as some quantum phases
are distinct only in the presence of certain symmetries. I will review
the concept of "symmetry-protected topological phases" and then
discuss our recent attempts in generalizing the notion of symmetry
protection of quantum phases.

---

ISSP Tokyo
Seminar Room TP 0.03
Contact: Simon Trebst