arXiv:1610.04727 · Physical Review Letters
Gapless Spin-Liquid Ground State in the S = 1 / 2 Kagome Antiferromagnet
Haijun Liao, Z. Y. Xie, Jialin Chen, Ziyi Liu, Haidong Xie, Rui-Zhen Huang, Bruce Normand, Tao Xiang
Abstract
The defining problem in frustrated quantum magnetism, the ground state of the nearest-neighbor S=1/2 antiferromagnetic Heisenberg model on the kagome lattice, has defied all theoretical and numerical methods employed to date. We apply the formalism of tensor-network states, specifically the method of projected entangled simplex states, which combines infinite system size with a correct accounting for multipartite entanglement. By studying the ground-state energy, the finite magnetic order appearing at finite tensor bond dimensions, and the effects of a next-nearest-neighbor coupling, we demonstrate that the ground state is a gapless spin liquid. We discuss the comparison with other numerical studies and the physical interpretation of this result.