Higher Order Structure in the Energy Landscapes of Model Glass Formers
The study of supercooled liquids and glasses remains one of the most divisive and
divided fields in modern physics. Despite a vast amount of effort and research time
invested in this topic, the answers to many central questions remain disputed and
incomplete. However, the link between the behaviour of supercooled liquids and
their energy landscapes is well established and widely accepted. Understanding this
link would be a key step towards resolving many of the mysteries and controversies
surrounding the glass transition. Therefore the study of glassy energy landscapes is
an important area of research.
In this thesis, I report some of the most detailed computational studies of glassy
potential energy landscapes ever performed. Using geometry optimisation techniques,
I have sampled the local minima and saddle points of the landscapes for
several supercooled liquids to analyse their dynamics and thermodynamics.
Some of my analysis follows previous work on the binary Lennard-Jones fluid
(BLJ), a model atomic liquid. BLJ is a fragile glass former, meaning that its
transport coefficients have super-Arrhenius temperature dependence, rather than
the more usual Arrhenius behaviour exhibited by strong liquids. The difference
in behaviour between these two classes of liquid has previously been attributed to
differing degrees of structure in the relevant energy landscapes.
I have studied models for both fragile and strong glass formers: the molecular
liquid ortho-terphenyl (OTP) and viscous silica (SiO