Prof. Pochung Chen (NTHU, junior center scientist of NCTS) collaborated with Prof. I. P. McCulloch (Centre for Engineered Quantum Systems, The University of Queensland, Australia), Prof. Ming-Chiang Chung (Dept. of Physics, NCHU) and Dr. S.-K. Yip (IOP and IAMS, Sinica) on the quantum critical phase of an SU(2) symmetric spin-2 chain obtained from spin-2 bosons in a one-dimensional lattice. In a previous study, they have studied the phase diagram of such a system and identified the existence of a quantum critical phase. In this work, they focus on the conformal theory describing the low energy physics of the whole critical phase. They use exact diagonalization and density-matrix renormalization group methods to obtain the energy spectra, finite-size scaling of the energies as well as the finite-size scaling of the entanglement entropy. Based on the finite-size scaling they estimate 
the value of the central charge and scaling dimension. From these results they identify the conformal field theory describing the whole critical phase to be the SU(3)_1 Wess-Zumino-Witten model. They find that, while the Hamiltonian is only SU(2) invariant, in this critical phase there is an emergent SU(3) symmetry in the thermodynamic limit. They study provides a potentially realizable cold atom system that can be used to demonstrate the emergent symmetry in the experiment.
 
http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.114.145301