Partition functions and stability criteria of topological insulators

Andrea Cappelli, Enrico Randellini
2013 Journal of High Energy Physics  
The non-chiral edge excitations of quantum spin Hall systems and topological insulators are described by means of their partition function. The stability of topological phases protected by time-reversal symmetry is rediscussed in this context and put in relation with the existence of discrete anomalies and the lack of modular invariance of the partition function. The _2 characterization of stable topological insulators is extended to systems with interacting and non-Abelian edge excitations.
doi:10.1007/jhep12(2013)101 fatcat:3wytjmv6njhavikgpouukzewsq