26th Australian Institute of Physics Congress and the Australian and New Zealand Conference on Optics and Photonics

Session

AIP CMM: Collective phenomena

CMM

9 Dec 2026, 14:30

Belinda Hutchinson Building (The University of Sydney )

97. Phonon Softening Anomalies and Phase Transformations

Trevor Finlayson (University of Melbourne)

09/12/2026, 14:30

AIP | Condensed Matter & Materials (CMM)

Contributed Oral

The term "soft phonon mode" was first introduced by Cochran in describing the lattice dynamical behaviour for certain ferroelectric crystals. Within the past forty years or so, the term has been applied, perhaps somewhat loosely, to describe almost any section of a phonon dispersion relation for which frequency decreases as temperature decreases. So the real relationship between "phonon...

308. Exact subtraction of electron self-interaction from the Kohn-Sham equations

John Ingall (The University of Newcastle, Australia)

09/12/2026, 14:45

AIP | Condensed Matter & Materials (CMM)

Contributed Oral

The effective design of new materials for sustainable energy conversion can be facilitated by the accurate prediction of electronic properties with moderate computational complexity and cost. The self-interaction error (SIE) of Kohn-Sham density functional theory (KS-DFT) leads to a non-physical, non-linear dependence of an orbital's energy on its own fractional occupation [Dabo et al., Phys....

534. Crystal Field Simulations Towards Enhanced Light-Matter Interactions

Li Hong Liu (The University of Sydney)

09/12/2026, 15:00

AIP | Condensed Matter & Materials (CMM)

Contributed Oral

Quantum networks are an important part of the future infrastructure that will allow transmission of quantum information between quantum computers. There are many promising hardware platforms for realising quantum networks including light-matter interactions in atomic systems (Kimble, Nature, 453, 2008) or solid-state systems (Chou et al, Nature, 561, 2018). Trivalent rare-earths embedded in...

629. Statistical physics of social media interaction

Tristram Alexander (University of Sydney)

09/12/2026, 15:15

AIP | Condensed Matter & Materials (CMM)

Contributed Oral

Social media platforms provide large-scale examples of interacting many-body systems, in which collective behaviour emerges from local interactions between heterogeneous agents. In this work, we study ideological asymmetry on Twitter/X using tools motivated by statistical physics and condensed matter theory. Users are assigned positions on a left-right ideological axis from their retweet...