2017/07/31 by Toshihiro Sato, Martin Hohenadler, Fakher F. Assaad · 1 citation
Physics and Astronomy · #Dirac (video compression format) #Dirac fermion #Fermion #Geometry #Monte Carlo method #Phase (matter) #Phase diagram #Phase transition #Physics #Physics of Superconductivity and Magnetism #Quantum #Quantum Monte Carlo #Quantum many-body systems #Quantum mechanics #Spinon #Statistics #Symmetry (geometry) #Theoretical physics #Topological Materials and Phenomena #Tricritical point #cond-mat.stat-mech #cond-mat.str-el #hep-th
paper · pdf · doi:10.1103/physrevlett.119.197203
published as Phys. Rev. Lett. 119, 197203 (2017) · 5 pages, 5 figures, to appear in Phys. Rev. Lett
arxiv created 2017/10/20 · openalex publication_date 2017/11/07 · arxiv updated 2017/11/15 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We consider a model of Dirac fermions in 2+1 dimensions with dynamically generated, anticommuting SO(3) Néel and Z2 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 Z3 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 the 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.