1997/06/17 by P. Lecheminant, B. Bernu, C. Lhuillier +2 · 1 citation
Physics and Astronomy · #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.56.2521
21 pages, Revtex
arxiv created 1997/06/17 · arxiv updated 2009/11/30
A group symmetry analysis of the low lying levels of the spin-1/2 kagomé Heisenberg antiferromagnet is performed for small samples up to N=27. This approach allows to follow the effect of quantum fluctuations when the sample size increases. The results contradict the scenario of ``order by disorder'' which has been advanced on the basis of large S calculations. A large enough second neighbor ferromagnetic exchange coupling is needed to stabilize the √ 3 × √ 3 pattern: the finite size analysis indicates a quantum critical transition at a non zero coupling.