Dirac Fermions with Competing Orders: Non-Landau Transition with Emergent Symmetry

Abstract

We consider a model of Dirac fermions in $2+1$ dimensions with dynamically generated, anticommuting SO(3) Néel and Z${}_2$ Kekulé mass terms that permits sign-free quantum Monte Carlo simulations. The phase diagram is obtained from finite-size scaling and includes a direct and continuous transition between the Néel and Kekulé phases. The fermions remain gapped across the transition, and our data support an emergent SO(4) symmetry unifying the two order parameters. While the bare symmetries of our model do not allow for spinon-carrying Z${}_3$ vortices in the Kekulé mass, the emergent SO(4) invariance permits an interpretation of the transition in terms of deconfined quantum criticality. The phase diagram also features a tricritical point at which Néel, Kekulé, and semimetallic phases meet. The present, sign-free approach can be generalized to a variety of other mass terms and thereby provides a new framework to study exotic critical phenomena.

5 pages, 5 figures, to appear in Phys. Rev. Lett

References in corpus (18)

• "Deconfined" quantum critical points
• Quantum criticality beyond the Landau-Ginzburg-Wilson paradigm
• Topological Mott Insulators
• Quantum spin-liquid emerging in two-dimensional correlated Dirac fermions
• Evidence for deconfined quantum criticality in a two-dimensional Heisenberg model with four-spin interactions
• Interactions and phase transitions on graphene's honeycomb lattice
• Electron fractionalization in two-dimensional graphenelike structures
• Absence of a Spin Liquid Phase in the Hubbard Model on the Honeycomb Lattice
• Theory of interacting electrons on the honeycomb lattice
• Fermionic quantum criticality in honeycomb and $\pi$-flux Hubbard models: Finite-size scaling of renormalization-group-invariant observables from quantum Monte Carlo
• Many-body spin Berry phases emerging from the $\pi$-flux state: antiferromagnetic/valence-bond-solid competition
• Duality between the deconfined quantum-critical point and the bosonic topological transition
• Fermionic Quantum Critical Point of Spinless Fermions on a Honeycomb Lattice
• Charged fermions coupled to ${\mathbb{Z}}_2$ gauge fields: Superfluidity, confinement and emergent Dirac fermions
• Charge instabilities and topological phases in the extended Hubbard model on the honeycomb lattice with enlarged unit cell
• A simple fermionic model of deconfined phases and phase transitions
• Phase diagram of the Kane-Mele-Coulomb model
• Phase diagram of interacting spinless fermions on the honeycomb lattice

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