paper

Emergent Symmetry at the Néel to Valence-Bond-Solid Transition

arXiv:1508.06668 · doi:10.1103/PhysRevLett.115.267203

Abstract

We show numerically that the `deconfined' quantum critical point between the Néel antiferromagnet and the columnar valence-bond-solid, for a square lattice of spin-1/2s, has an emergent symmetry. This symmetry allows the Néel vector and the valence-bond-solid order parameter to be rotated into each other. It is a remarkable 2+1-dimensional analogue of the symmetry that appears in the scaling limit for the spin-1/2 Heisenberg chain. The emergent is strong evidence that the phase transition in the 2+1D system is truly continuous, despite the violations of finite-size scaling observed previously in this problem. It also implies surprising relations between correlation functions at the transition. The symmetry enhancement is expected to apply generally to the critical two-component Abelian Higgs model (non-compact model). The result indicates that in three dimensions there is an -symmetric conformal field theory which has no relevant singlet operators, so is radically different to conventional Wilson-Fisher-type conformal field theories.

4+epsilon pages, 6 figures

References in corpus (10)

Cited by in corpus (146)