Symmetry-protected topological phases and orbifolds: Generalized Laughlin's argument
Symmetry-protected topological phases and orbifolds: Generalized Laughlin's argument
We consider nonchiral symmetry-protected topological phases of matter in two spatial dimensions protected by a discrete symmetry such as ${\mathbb{Z}}_{K}$ or ${\mathbb{Z}}_{K}\ifmmode\times\else\texttimes\fi{}{\mathbb{Z}}_{K}$ symmetry. We argue that modular invariance/noninvariance of the partition function of the one-dimensional edge theory can be used to diagnose whether, by adding a suitable potential, the edge …