Activated scaling in disorder-rounded first-order quantum phase transitions

作者：Bellafard Arash; Chakravarty Sudip

来源：Physical Review B, 2016, 94(9): 094408.

DOI：10.1103/PhysRevB.94.094408

First-order phase transitions, classical or quantum, subject to randomness coupled to energylike variables (bond randomness) can be rounded, resulting in continuous transitions (emergent criticality). We study perhaps the simplest such model, the 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.

• 出版日期2016-9-7