Year: 2020
Type: article
Abstract: We present a study of a simple model antiferromagnet consisting of a sum of nearest-neighbor $\mathrm{SO}(N)$ 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 ${\mathbb{Z}}_{2}$ topological phase. Supporting this assertion, a numerical study of the entanglement entropy in the sign free model shows a quantized topological contribution.
Authors: Matthew S. Block, Jonathan D'Emidio, Ribhu K. Kaul
Language: Latvian
Subfield: Condensed Matter Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Funder: National Science Foundation
OpenAlex ID: W2950261218