Abstract
Exact diagonalizations of the spin-1/2 Heisenberg model on the checkerboard lattice have been performed for sizes up to in the full Hilbert space and in the restricted subspace of first neighbor dimers. This antiferromagnet does not break SU(2) symmetry and displays long-range order in four-spin plaquettes. Both the symmetry properties of the spectrum and various correlations functions are extensively studied. At variance with the kagomé antiferromagnet, the Heisenberg quantum model on a checkerboard lattice is a valence bond crystal. Some results concerning the three-dimensional spin-1/2 pyrochlore magnet (for sizes 16 and 32) are also shown: this system could behave differently from its two-dimensional analog.
- Received 3 August 2001
DOI:https://doi.org/10.1103/PhysRevB.67.054411
©2003 American Physical Society