A surprise observation of negative mass in exciton-polaritons has added yet another dimension of weirdness to these strange light-matter hybrid particles. Dr Matthias Wurdack, Dr Tinghe Yun and Dr Eliezer Estrecho from the Department of Quantum Sciences and Technology (QST) were experimenting with exciton polaritons when they realised that under certain conditions the dispersion became…

Multidimensional coherent spectroscopy (MDCS) on monolayer WS2 reveals Fermi polaron interactions Phase-space filling drives new optical selection rules, where excitons compete for the same electron Identification of a novel, cooperatively-bound exciton-exciton-electron state Recent Australian-led research has provided a world’s first measurement of interactions between Fermi polarons in…

First observation of excitonic insulator New exotic state was first predicted in 1960s A University of Wollongong / Monash University collaboration has found evidence of a new phase of matter predicted in the 1960s: the excitonic insulator. The unique signatures of an excitonic insulating phase were observed in antimony Sb(110) nanoflakes. The findings provide a novel strategy to…

First snapshot of exciton-polariton Bose-Einstein condensation (BEC) in an inorganic semiconductor Unique opportunity to understand details of BEC without statistical averaging Key to fundamental understanding of exciton-polaritons An ANU advance provides never-before-achieved ‘snapshot’ of Bose-Einstein condensation. Previously, observations of exciton-polaritons in a Bose-Einstein…