Competing states in the SU(3) Heisenberg model on the honeycomb lattice: Plaquette valence-bond crystal versus dimerized color-ordered state
Abstract
Conflicting predictions have been made for the ground state of the SU(3) Heisenberg model on the honeycomb lattice: Tensor network simulations found a plaquette order [Zhao , Phys. Rev. BPRBMDO1098-012110.1103/PhysRevB.85.134416 85, 134416 (2012)], where singlets are formed on hexagons, while linear flavor-wave theory suggested a dimerized, color-ordered state [Lee and Yang, Phys. Rev. BPRBMDO1098-012110.1103/PhysRevB.85.100402 85, 100402 (2012)]. In this work we show that the former state is the true ground state by a systematic study with infinite projected-entangled pair states (iPEPS), for which the accuracy can be systematically controlled by the so-called bond dimension D. Both competing states can be reproduced with iPEPS by using different unit cell sizes. For small D the dimer state has a lower variational energy than the plaquette state; however, for large D it is the latter which becomes energetically favorable. The plaquette formation is also confirmed by exact diagonalizations and variational Monte Carlo studies, according to which both the dimerized and plaquette states are nonchiral flux states.
- Publication:
-
Physical Review B
- Pub Date:
- May 2013
- DOI:
- 10.1103/PhysRevB.87.195113
- arXiv:
- arXiv:1302.1108
- Bibcode:
- 2013PhRvB..87s5113C
- Keywords:
-
- 67.85.-d;
- 71.10.Fd;
- 75.10.Jm;
- 02.70.-c;
- Ultracold gases trapped gases;
- Lattice fermion models;
- Quantized spin models;
- Computational techniques;
- simulations;
- Condensed Matter - Strongly Correlated Electrons;
- Condensed Matter - Quantum Gases
- E-Print:
- 11 pages, 12 figures, small changes, added more references