Quantum Phase Transitions beyond the Landau's Paradigm in Sp(4) Spin System

Abstract

We propose quantum phase transitions beyond the Landau's paradigm of Sp(4) spin Heisenberg models on the triangular and square lattices, motivated by the exact Sp(4)$\simeq$ SO(5) symmetry of spin-3/2 fermionic cold atomic system with only $s-$wave scattering. On the triangular lattice, we study a phase transition between the $\sqrt{3}\times \sqrt{3}$ spin ordered phase and a $Z_2$ spin liquid phase, this phase transition is described by an O(8) sigma model in terms of fractionalized spinon fields, with significant anomalous scaling dimensions of spin order parameters. On the square lattice, we propose a deconfined critical point between the Neel order and the VBS order, which is described by the CP(3) model, and the monopole effect of the compact U(1) gauge field is expected to be suppressed at the critical point.

6 pages, 3 figures

References in corpus (7)

• "Deconfined" quantum critical points
• Quantum criticality beyond the Landau-Ginzburg-Wilson paradigm
• Scaling in the Fan of an Unconventional Quantum Critical Point
• Competing orders in one dimensional spin 3/2 fermionic systems
• Néel and Spin-Peierls ground states of two-dimensional SU(N) quantum antiferromagnets
• Exact spontaneous plaquette ground states for high-spin ladder models
• Resonating singlet valence plaquettes