The concept of geometric phase has revolutionized our understanding of state evolution in both classical and quantum physics and has led to the discovery of topological insulators. Geometric phase arising from the SO(3) group rotation of states in real space is called spin-redirection phase and can be observed in vector waves, such as light. It is commonly believed that such a phase should be absent in scalar waves, such as airborne sound. Dr. Shubo WANG and his collaborators theoretically and experimentally demonstrated, for the first time, spin-redirection phase effects in airborne sound. This is achieved by exploiting sound vortex traveling through a path that bestows a nontrivial winding of the wave vector in momentum space. It provides the important insight that the topological properties of different parameter spaces, e.g. real space and momentum space, are correlated, and one can serve as the origin of the other. The work lays the foundation for future exploitation of spin-redirection phase as a new degree of freedom for the manipulation of scalar waves.
Read more at Science Advances: http://advances.sciencemag.org/content/4/2/eaaq1475
Related article: http://www.cityu.edu.hk/vprt/news/2018/spin-redirection-phase-of-sound-wave-demonstrated-for-the-first-time/
23 Feb 2018