Exact Spin Liquid Ground States of the Quantum Dimer Model on the Square and Honeycomb Lattices
Abstract
We study a generalized quantum hard-core dimer model on the square and honeycomb lattices, allowing for first and second neighbor dimers. At generalized Rokhsar-Kivelson points, the exact ground states can be constructed, and ground-state correlation functions can be equated to those of interacting (1+1)-dimensional Grassmann fields. When the concentration of second neighbor dimers is small, the ground-state correlations are shown to be short ranged corresponding to a (gaped) spin liquid phase. On a 2-torus, the ground states exhibit fourfold topological degeneracy. On a finite cylinder we have found a dramatic even-odd effect depending on the circumference and propose that this can be used as a numerical diagnostic of gapped spin-liquid phases, more generally.
- Publication:
-
Physical Review Letters
- Pub Date:
- June 2012
- DOI:
- 10.1103/PhysRevLett.108.247206
- arXiv:
- arXiv:1112.1702
- Bibcode:
- 2012PhRvL.108x7206Y
- Keywords:
-
- 75.10.Kt;
- 03.65.Vf;
- 31.15.xk;
- 75.25.-j;
- Phases: geometric;
- dynamic or topological;
- Path-integral methods;
- Condensed Matter - Strongly Correlated Electrons;
- Condensed Matter - Statistical Mechanics
- E-Print:
- 4 pages + supplemental materials, 2 figures, added references