1307.8131 (Cenke Xu)

Three Dimensional Z2 Topological Phases enriched by Time-Reversal
Symmetry    [PDF]

Cenke Xu

We study three dimensional Z2 topological phases enriched by time-reversal symmetry with bosonic bulk excitations. Some of these phases can be constructed by simply coupling the three dimensional symmetry protected topological phases with Z2 and time-reversal symmetry to a deconfined Z2 gauge field. Besides these simple phases, we also construct two special root phases, whose boundary can have an extra Z2 topological order in addition to their bulk topological order, and the boundary anyon excitations can have fractional time-reversal transformation T with T^4 = -1. In particular, the boundary e and m anyons of one of the two root phases are interchanged under time-reversal transformation, and they must be degenerate and orthogonal with each other. Eventually we obtain 8 different time-reversal enriched Z2 topological phases with bosonic bulk excitations in three dimension.

View original: http://arxiv.org/abs/1307.8131