image: Half quantum vortices are the elementary excitations of spinor superfluids. They are characterized by a pi rotation of the fluid phase and a pi rotation of the spin when circumventing the vortex core. However they can also be depicted as a full vortex in the spin up fluid (forklike dislocation in the red fringe pattern) and its absence in the spin down fluid (straight fringes in blue fringe pattern). This image relates to an article that appeared in the Nov. 13 issue of Science, published by AAAS. The study, by Dr. K.G. Lagoudakis of École Polytechnique Fédérale de Lausanne in Lausanne, Switzerland and colleagues, was titled, "Observation on Half-Quantum Vortices in an Exciton-Polariton Condensate." view more
Credit: Image © Science/AAAS