Field-induced ordering in critical antiferromagnets (original) (raw)

The user has requested enhancement of the downloaded file. All in-text references underlined in blue are added to the original document and are linked to publications on ResearchGate, letting you access and read them immediately. arXiv:cond-mat/9812341v1 [cond-mat.stat-mech] 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 summarised 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 (dTc/dH) T =H=0 = 4.74 ± 0.15. For SPAF-3 we provided evidence that the zero-field correlation length diverges as ξ(T → 0, H = 0) ≃ exp(a/T x ), with x = 1.08 ± 0.13, through analysis of the critical curve at H = 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, η = 1/3; (b) H = 0: c = 1/2, η = 1/4.