Thursday, April 4, 2013

1304.0783 (Dominic V. Else et al.)

The hidden symmetry-breaking picture of symmetry-protected topological
order
   [PDF]

Dominic V. Else, Stephen D. Bartlett, Andrew C. Doherty
We generalize the hidden symmetry-breaking picture of symmetry-protected topological (SPT) order developed by Kennedy and Tasaki in the context of the Haldane phase. Our generalization applies to a wide class of SPT phases in one-dimensional spin chains, protected by an on-site representation of a finite abelian group. This generalization takes the form of a non-local unitary map that relates local symmetry-respecting Hamiltonians in an SPT phase to local Hamiltonians in a symmetry-broken phase. Using this unitary, we establish a relation between the two-point correlation functions that characterize fully symmetry-broken phases with the string-order correlation functions that characterise the SPT phases, therefore establishing the perspective in these systems that SPT phases are characterised by hidden symmetry-breaking. Our generalization is also applied to systems with continuous symmetries, including SO(2k+1) and SU(k).
View original: http://arxiv.org/abs/1304.0783

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