Phys. Rev. B 68, 144422 (2003) [17 pages]Bond order from disorder in the planar pyrochlore magnetReceived 27 January 2003; revised 16 May 2003; published 17 October 2003 We study magnetic order in the Heisenberg antiferromagnet on the checkerboard lattice, a two-dimensional version of the pyrochlore network with strong geometric frustration. By employing the semiclassical (1/S) expansion we find that quantum fluctuations of spins induce a long-range order that breaks the fourfold rotational symmetry of the lattice. The ordered phase is a valence-bond crystal. We discuss similarities and differences with the extreme quantum case S=1/2 and find a useful phenomenology to describe the bond-ordered phases. © 2003 The American Physical Society URL:
http://link.aps.org/doi/10.1103/PhysRevB.68.144422
DOI:
10.1103/PhysRevB.68.144422
PACS:
75.10.Hk
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