We investigate the nature of quantum spin liquid (QSL) phase of the spin-1/2 nearest-neighbor XXZ antiferromagnet on the kagome lattice. Recent numerical calculations suggest that such a kagome spin liquid is insensitive to the XXZ anisotropy and is adjacent to a chiral spin liquid phase. Reformulating the problem in terms of a U(1) lattice gauge theory with dynamical bosonic spinons, we propose that the kagome spin liquid can be understood as a deconfined critical phase extended by the U(1) gauge fluctuation from a deconfined critical point between a symmetry-protected topological phase and a superfluid phase. Crucially, the stability of this QSL is ensured by the gauge fluctuation and hence our description necessarily falls beyond the conventional mean-field constructions of QSLs. Our work also makes an interesting connection between the critical spin liquid, deconfined criticality, symmetry protected topological phase and topological order.
@article{arxiv.1512.05381,
title = {Kagome spin liquid: a deconfined critical phase driven by $U(1)$ gauge fluctuation},
author = {Yin-Chen He and Yohei Fuji and Subhro Bhattacharjee},
journal= {arXiv preprint arXiv:1512.05381},
year = {2016}
}