We present a study of a simple model antiferromagnet consisting of a sum of nearest-neighbor SO(N) singlet projectors on the kagome lattice. Our model shares some features with the popular S=1/2 kagome antiferromagnet but is specifically designed to be free of the sign problem of quantum Monte Carlo. In our numerical analysis, we find as a function of N a quadrupolar magnetic state and a wide range of a quantum spin liquid. A solvable large-N generalization suggests that the quantum spin liquid in our original model is a gapped Z2 topological phase. Supporting this assertion, a numerical study of the entanglement entropy in the sign free model shows a quantized topological contribution.
|Journal||Physical Review B|
|State||Published - Jan 9 2020|
Bibliographical noteFunding Information:
Acknowledgments. The computational work presented here was carried out using the XSEDE awards TG-DMR130040 and TG-DMR140061. Financial support was received through NSF DMR-1611161.
© 2020 American Physical Society.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics