1208.0697 (Kasper Duivenvoorden et al.)

A discriminating string order parameter for topological phases of gapped
SU(N) spin chains    [PDF]

Kasper Duivenvoorden, Thomas Quella

One-dimensional gapped spin chains with SU(N) symmetry are known to possess N different topological phases. In this paper, we introduce a non-local string order parameter which characterizes each of these N phases unambiguously. Numerics confirm that our order parameter may be used to extract a quantized topological invariant given a non-degenerate gapped ground state wave function. Discontinuous jumps in the discrete topological order that arise when varying physical couplings in the Hamiltonian may be used to detect quantum phase transitions.

View original: http://arxiv.org/abs/1208.0697