Degeneracy and Strong Fluctuation-Induced First-Order Phase Transition in the Dipolar Pyrochlore Antiferromagnet
arXiv:cond-mat/0507289 · doi:10.1103/PhysRevB.72.184408
Abstract
We show that a continuous set of degenerate critical soft modes strongly enhances the first-order character of a fluctuation-induced first-order transition in the pyrochlore dipolar Heisenberg antiferromagnet. Such a degeneracy seems essential to explain the strong first-order transition recently observed in Gd(2)Sn(2)O(7). We present some evidence from Monte-Carlo simulations and a perturbative renormalization group expansion.
8 pages, 9 figures, new version to appear in PRB, added refs