Spatially anisotropic Heisenberg kagome antiferromagnet

• Published in: Journal of physics. Condensed matter 2007-04, Vol.19 (14), p.145255-145255 (6)
• Main Authors: Apel, W, Yavors’kii, T, Everts, H-U
• Format: Article
• Language: English
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; General theory and models of magnetic ordering; Magnetic properties and materials; Physics
• ISSN: 0953-8984; 1361-648X
• DOI: 10.1088/0953-8984/19/14/145255

In the search for spin-1/2 kagome antiferromagnets, the mineral volborthite has recently been the subject of experimental studies (Hiroi et al 2001 J. Phys. Soc. Japan 70 3377; Fukaya et al 2003 Phys. Rev. Lett. 91 207603; Bert et al 2004 J. Phys.: Condens. Matter 16 S829; Bert et al 2005 Phys. Rev. Lett. 95 087203). It has been suggested that the magnetic properties of this material are described by a spin-1/2 Heisenberg model on the kagome lattice with spatially anisotropic exchange couplings. We report on investigations of the symmetric generalization of this model in the large limit. We obtain a detailed description of the dependence of possible ground states on the anisotropy and on the spin length S. A fairly rich phase diagram with a ferrimagnetic phase, incommensurate phases with and without long-range order and a decoupled chain phase emerges.