Emergence of magnetic long-range order in kagome quantum antiferromagnets

摘要: The existence of a spin-liquid ground state the $s=1/2$ Heisenberg kagome antiferromagnet (KAFM) is well established. Meanwhile, also for $s=1$ KAFM evidence absence magnetic long-range order (LRO) was found. Magnetic LRO in KAFMs can emerge by increasing spin quantum number $s$ to $s>1$ and an easy-plane anisotropy. In present paper we discuss route including isotropic interlayer coupling (ILC) $J_\perp$ as anisotropy layers using coupled-cluster method high orders approximation. We consider ferro- antiferromagnetic $J_\perp$. To general question crossover from purely two-dimensional (2D) quasi-2D finally three-dimensional system simplest model stacked (unshifted) layers. Although ILC real compounds often more sophisticated, such geometry be relevant barlowite. find that strictly 2D $XXZ$ survives finite ILC, where region shrinks monotonously with If becomes large enough (about 15\% intralayer case about 4\% $XY$ limit) established, $q=0$ symmetry favorable if moderate strength. strength further increases, $\sqrt{3}\times \sqrt{3}$ become against LRO.