Spatially anisotropic Heisenberg kagome antiferromagnet

We study the quasi-one-dimensional limit of the spin-1/2 quantum Heisenberg antiferromagnet on the kagome lattice. The lattice is divided into antiferromagnetic spin chains (exchange J) that are weakly coupled via intermediate “dangling” spins (exchange J^′). Using one-dimensional bosonization, renormalization-group methods, and current algebra techniques, the ground state is determined in the limit J^′⪡J. We find that the dangling spins and chain spins form a spiral with O(1) and O(J^′/J) static moments, respectively, atop of which the chain spins exhibit a smaller O[(J^′/J)²] antiferromagnetically ordered component along the axis perpendicular to the spiral plane.