Fractal free energy landscapes in structural glasses

Condensed Matter journal club

Fractal free energy landscapes in structural glasses

  • Event time: 11:30am until 12:30pm
  • Event date: 2nd March 2018
  • Speaker: (School of Physics & Astronomy, University of Edinburgh)
  • Location: 2511

Event details

Glasses are amorphous solids whose constituent particles are caged by their neighbours and thus cannot flow. This sluggishness is often ascribed to the free energy landscape containing multiple minima (basins) separated by high barriers. Here we show, using theory and numerical simulation, that the landscape is much rougher than is classically assumed. Deep in the glass, it undergoes a ‘roughness transition’ to fractal basins, which brings about isostaticity and marginal stability on approaching jamming. Critical exponents for the basin width, the weak force distribution and the spatial spread of quasi-contacts near jamming can be analytically determined.  Their value is found to be compatible with numerical observations. This advance incorporates the jamming transition of granular materials into the framework of glass theory. Because temperature and pressure control what features of the landscape are experienced, glass mechanics and transport are expected to reflect the features of the topology we discuss here.

Event resources

About Condensed Matter journal club

Given the diversity of research in the CM group, chosen topics vary widely. We tend to stick to high-impact journals - Nature, Science, PNAS and PRL have been popular - but this is not prescriptive..

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