From SU(2)${}_5$ to SU(2)${}_3$ Wess-Zumino-Witten transitions in a frustrated spin-5/2 chain

Abstract

We investigate the properties of a frustrated spin-5/2 chain with next-nearest neighbor two and three-site interactions, with two questions in mind: the nature of the transition into the dimerized phase induced by the three-site interaction, and the possible presence of a critical floating phase at intermediate values of the next-nearest neighbor interaction. We provide strong evidence that the continuous transition into the dimerized phase, which has been found to be generically in the Wess-Zumino-Witten SU(2)${}_{2S}$ universality class up to spin $S=2$, is SU(2)${}_5$ only at two isolated points of the phase diagram, and that it is SU(2)${}_3$ in between, in agreement with the presence of two relevant operators allowed by symmetry for SU(2)${}_5$, and with the conservation of the parity of the level index along the renormalization flow between SU(2)${}_k$ theories with different values of $k$. We also find that the dimerization induced by the next-nearest neighbor interaction is a three step process, with first a small partially dimerized phase followed by a broad critical floating phase with incommensurate correlations before the fully dimerized phase is reached. Implications for the iron oxide ${\mathrm{Bi}}_3{\mathrm{FeMo}}_2{\mathrm{O}}_{12}$ are briefly discussed.

10 pages, 9 figures

References in corpus (4)

• The density-matrix renormalization group in the age of matrix product states
• Realization of higher Wess-Zumino-Witten models in spin chains
• Spontaneous dimerization, critical lines, and short-range correlations in a frustrated spin-1 chain
• Magnetic properties of S = 5/2 anisotropic triangular chain Bi3FeMo2O12