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Power-law correlated phase in random-field XY models and randomly pinned charge-density waves

Ronald Fisch
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Abstract

Monte Carlo simulations have been used to study the Z6 ferromagnet in a random field on simple cubic lattices, which is a simple model for randomly pinned charge-density waves. The random field is chosen to have infinite strength on a fraction x of the sites of the lattice, and to be zero on the remaining sites. For x= 1/16 there are two phase transitions. At low temperature there is a ferromagnetic phase, which is stabilized by the six-fold nonrandom anisotropy. The intermediate temperature phase is characterized by a |k|^(-3) decay of two-spin correlations, but no true ferromagnetic order. At the transition between the power-law correlated phase and the paramagnetic phase the magnetic susceptibility diverges, and the two-spin correlations decay approximately as |k|^(-2.87).

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Ronald Fisch. 1996-08-07. Power-law correlated phase in random-field XY models and randomly pinned charge-density waves. https://doi.org/10.1103/physrevb.55.8211

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