Visualising Berry phase and diabolical points in a quantum exciton-polariton billiard
MetadataShow full item record
Diabolical points (spectral degeneracies) can naturally occur in spectra of two-dimensional quantum systems and classical wave resonators due to simple symmetries. Geometric Berry phase is associated with these spectral degeneracies. Here, we demonstrate a diabolical point and the corresponding Berry phase in the spectrum of hybrid light-matter quasiparticles – exciton-polaritons in semiconductor microcavities. It is well known that sufficiently strong optical pumping can drive excitonpolaritons to quantum degeneracy, whereby they form a macroscopically populated quantum coherent state similar to a Bose-Einstein condensate. By pumping a microcavity with a spatially structured light beam, we create a two-dimensional quantum billiard for the exciton-polariton condensate and demonstrate a diabolical point in the spectrum of the billiard eigenstates. The fully reconfigurable geometry of the potential walls controlled by the optical pump enables a striking experimental visualisation of the Berry phase associated with the diabolical point. The Berry phase is observed and measured by direct imaging of the macroscopic exciton-polariton probability densities.
Estrecho , E , Gao , T , Brodbeck , S , Kamp , M , Schneider , C , Höfling , S , Truscott , A G & Ostrovskaya , E A 2016 , ' Visualising Berry phase and diabolical points in a quantum exciton-polariton billiard ' Scientific Reports , vol 6 , 37653 . DOI: 10.1038/srep37653
Copyright the Author(s) 2016. This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/
DescriptionThis work is supported by the Australian Research Council and the State of Bavaria.
Items in the St Andrews Research Repository are protected by copyright, with all rights reserved, unless otherwise indicated.