2001/12/31 by Naveen Surendran, Ravi Shankar, R. Shankar
Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #Magnetic and transport properties of perovskites and related materials #Physics of Superconductivity and Magnetism #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.66.024415
published as Phys. Rev B 66, 024415 (2002) · Published version; slightly expanded
openalex publication_date 2002/07/10 · arxiv created 2002/12/27 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We construct Heisenberg antiferromagnetic models in arbitrary dimensions that have isotropic valence-bond crystals (VBC's) as their exact ground states. The d=2 model is the Shastry-Sutherland model. In the three-dimensional case we show that it is possible to have a lattice structure, analogous to that of SrCu2(BO3)2, where the stronger bonds are associated with shorter bond lengths. A dimer mean-field theory becomes exact at \stackrel\ensuremath→d\ensuremath∞ and a systematic 1/d expansion can be developed about it. We study the N'eel-VBC transition at large d and find that the transition is first order in even but second order in odd dimensions.