Quantum Destruction of Spiral Order in Two Dimensional Frustrated Magnets

Abstract

We study the fate of spin-1/2 spiral-ordered two-dimensional quantum antiferromagnets that are disordered by quantum fluctuations. A crucial role is played by the topological point defects of the spiral phase, which are known to have a Z2 character. Previous works established that a nontrivial quantum spin-liquid phase results when the spiral is disordered without proliferating the Z2 vortices. Here, we show that when the spiral is disordered by proliferating and condensing these vortices, valence-bond solid ordering occurs due to quantum Berry phase effects. We develop a general theory for this latter phase transition and apply it to a lattice model. This transition potentially provides a new example of a Landau-forbidden deconfined quantum critical point.

12 pages (Extended and appendix added)

References in corpus (8)

• "Deconfined" quantum critical points
• Quantum criticality beyond the Landau-Ginzburg-Wilson paradigm
• Evidence for deconfined quantum criticality in a two-dimensional Heisenberg model with four-spin interactions
• Quantum magnetism and criticality
• Ordering in spatially anisotropic triangular antiferromagnets
• Global phase diagrams of frustrated quantum antiferromagnets in two dimensions: doubled Chern-Simons theory
• Mutual Chern-Simons theory for Z_2 topological order
• Quantum spin nematics, dimerization, and deconfined criticality in quasi-one dimensional spin-1 magnets

Cited by in corpus (6)

• Ground States of Spin-1/2 Triangular Antiferromagnets in a Magnetic Field
• Spin correlations and phase diagram of the perturbed Kitaev model
• Phases and Quantum Phase Transitions in an Anisotropic Ferromagnetic Kitaev-Heisenberg-$\Gamma$ Magnet
• Self-dual criticality in three-dimensional ${\mathbb{Z}}_2$ gauge theory with matter
• Higher categorical groups and the classification of topological defects and textures
• Phases and Quantum Phase Transitions in Anisotropic Antiferromagnetic Kitaev-Heisenberg-$\Gamma$ magnet