Abstract
We study the three-dimensional model with a anisotropic term. At temperatures this dangerously irrelevant perturbation is relevant only above a length scale , which diverges as a power of the correlation length, . Below the order parameter is U(1) symmetric. We derive the full scaling function controlling the emergence of U(1) symmetry and use Monte Carlo results to extract the exponent for . We find that , with only marginally larger than 1. We discuss these results in the context of U(1) symmetry at deconfined quantum-critical points separating antiferromagnetic and valence-bond-solid states in quantum spin systems.
- Received 11 April 2007
DOI:https://doi.org/10.1103/PhysRevLett.99.207203
©2007 American Physical Society