Topological Entanglement Rényi Entropy and Reduced Density Matrix Structure

We generalize the topological entanglement entropy to a family of topological Rényi entropies parametrized by a parameter , in an attempt to find new invariants for distinguishing topologically ordered phases. We show that, surprisingly, all topological Rényi entropies are the same, independent of for all nonchiral topological phases. This independence shows that topologically ordered ground-state wave functions have reduced density matrices with a certain simple structure, and no additional universal information can be extracted from the entanglement spectrum. ©2009 The American Physical Society