Bond disorder induced criticality of the three-color Ashkin-Teller model

Abstract

An intriguing result of statistical mechanics is that a first-order phase transition can be rounded by disorder coupled to energy-like variables. In fact, even more intriguing is that the rounding may manifest itself as a critical point, quantum or classical. In general, it is not known, however, what universality classes, if any, such criticalities belong to. In order to shed light on this question we examine in detail the disordered three-color Ashkin-Teller model by Monte Carlo methods. Extensive analyses indicate that the critical exponents define a new universality class. We show that the rounding of the first-order transition of the pure model due to the impurities is manifested as criticality. However, the magnetization critical exponent, (β), and the correlation length critical exponent, (ν), are found to vary with disorder and the four-spin coupling strength, and we conclusively rule out that the model belongs to the universality class of the two-dimensional Ising model.

4.1 pages, 8 figures

References in corpus (1)

• Rounding by disorder of first-order quantum phase transitions: emergence of quantum critical points

Cited by in corpus (7)

• Emerging criticality in the disordered three-color Ashkin-Teller model
• Rounding of a first-order quantum phase transition to a strong-coupling critical point
• Ising universality in the two-dimensional Blume-Capel model with quenched random crystal field
• The effect of quenched bond disorder on first-order phase transitions
• Corrections to scaling in the dynamic approach to the phase transition with quenched disorder
• Nonuniversality in random criticality
• Emergent universal critical behavior of the 2D $N$-color Ashkin-Teller model in the presence of correlated disorder