Field-induced ordering in critical antiferromagnets
S. L. A. de Queiroz, Thereza Paiva, Jorge S. Sá Martins +1 more
Transfer-matrix scaling methods have been used to study critical properties of field-induced phase transitions of two distinct two-dimensional antiferromagnets with discrete-symmetry order parameters: triangular-lattice Ising systems (TIAF) and the square-lattice three-state Potts model (SPAF-3). Our main findings are summarized as follows. For TIAF, we have shown that the critical line leaves the zero-temperature, zero-field fixed point at a finite angle. Our best estimate of the slope at the origin is ${(dT}_{c}{/dH)}_{T=H=0}=4.74\ifmmode\pm\else\textpm\fi{}0.15.$ For SPAF-3 we provided evidence that the zero-field correlation length diverges as $\ensuremath{\xi}(\stackrel{\ensuremath{\rightarrow}}{T}0, H=0)\ensuremath{\simeq}\mathrm{exp}{(a/T}^{x}),$ with $x=1.08\ifmmode\pm\else\textpm\fi{}0.13,$ through analysis of the critical curve at $H\ensuremath{\ne}0$ plus crossover arguments. For SPAF-3 we have also ascertained that the conformal anomaly and decay-of-correlations exponent behave as (a) $H=0:c=1, \ensuremath{\eta}=1/3.$ (b) $H\ensuremath{\ne}0:c=1/2, \ensuremath{\eta}=1/4.$
arXiv:cond-mat/9812341•Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics•Mar 1, 1999•16 citations