Activated scaling in disorder rounded first-order quantum phase transitions

Abstract

First-order phase transitions, classical or quantum, subject to randomness coupled to energy-like variables (bond randomness) can be rounded, resulting in continuous transitions (emergent criticality). We study perhaps the simplest such model, quantum three-color Ashkin-Teller model and show that the quantum critical point in $(1+1)$ dimension is an unusual one, with activated scaling at the critical point and Griffiths-McCoy phase away from it. The behavior is similar to the transverse random field Ising model, even though the pure system has a first-order transition in this case. We believe that this fact must be attended to when discussing quantum critical points in numerous physical systems, which may be first-order transitions in disguise.

6 pages, 5 figures

References in corpus (5)

• Rounding by disorder of first-order quantum phase transitions: emergence of quantum critical points
• Rounding of a first-order quantum phase transition to a strong-coupling critical point
• Bond disorder induced criticality of the three-color Ashkin-Teller model
• Strong-randomness phenomena in quantum Ashkin-Teller models
• The effect of quenched bond disorder on first-order phase transitions

Cited by in corpus (3)

• Strong Disorder RG approach - a short review of recent developments
• Monte Carlo simulations of the disordered three-color quantum Ashkin-Teller chain
• Wetting transition in the McCoy-Wu model