Microscopic models of mode-coupling theory : the F12 scenario

• Autor(a) principal: Arenzon, Jeferson Jacob
• Data de Publicação: 2012
• Outros Autores: Sellitto, Mauro
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UFRGS
• Texto Completo: http://hdl.handle.net/10183/205125
• topic: Pontos criticos; Fractais; Transicao vitrea; Percolação; Sistemas de spin; Super-resfriamento; Termodinâmica

We provide extended evidence that mode-coupling theory (MCT) of supercooled liquids for the F12 schematic model admits a microscopic realization based on facilitated spin models with tunable facilitation. Depending on the facilitation strength, one observes two distinct dynamical glass transition lines—continuous and discontinuous—merging at a dynamical tricritical-like point with critical decay exponents consistently related by MCT predictions. The mechanisms of dynamical arrest can be naturally interpreted in geometrical terms: the discontinuous and continuous transitions correspond to bootstrap and standard percolation processes, in which the incipient spanning cluster of frozen spins forms either a compact or a fractal structure, respectively. Our cooperative dynamical facilitation picture of glassy behavior is complementary to the one based on disordered systems and can account for higher-order singularity scenarios in the absence of a finite temperature thermodynamic glass transition. We briefly comment on the relevance of our results to finite spatial dimensions and to the F13 schematic model.