Effect of Random Impurities on Fluctuation-Driven First Order Transitions

Journal article

We analyse the effect of quenched uncorrelated randomness coupling to the local energy density of a model consisting of N coupled two-dimensional Ising models. For N>2 the pure model exhibits a fluctuation-driven first order transition, characterised by runaway renormalisation group behaviour. We show that the addition of weak randomness acts to stabilise these flows, in such a way that the trajectories ultimately flow back towards the pure decoupled Ising fixed point, with the usual critical exponents alpha=0, nu=1, apart from logarithmic corrections. We also show by examples that, in higher dimensions, such transitions may either become continuous or remain first order in the presence of randomness.

Authors: Cardy, J

• Publication status: Published
• Journal: JOURNAL OF PHYSICS A-MATHEMATICAL AND GENERAL
• Volume: 29
• Issue: 9
• Pages: 1897-1904
• Publication date: 1995-11-23
• DOI: 10.1088/0305-4470/29/9/006
• EISSN: 1361-6447
• ISSN: 0305-4470
• Keywords: cond-mat