Dynamics of optical vortices in van der Waals materials
Abstract
Quantized vortices are topological defects found in different two-dimensional geometries, from liquid crystals to ferromagnets, famously involved in spontaneous symmetry breaking and phase transitions. Their optical counterparts appear in planar geometries as a universal wave phenomenon, possessing topologically protected orbital angular momentum (OAM). So far, the spatiotemporal dynamics of optical vortices, including vortex-pair creation and annihilation, has been observed only in Bose–Einstein condensates. Here we observe optical vortices in van der Waals materials and measure their dynamics, including events of pair creation and annihilation. Vortices of opposite OAM are involved in pair creation/annihilation events, and their relative signs determine the surrounding field profile throughout their motion. The vortices are made of phonon polaritons in hexagonal boron nitride, which we directly probe using free electrons in an ultrafast transmission electron microscope. Our findings promote future investigations of vortex phenomena in van der Waals platforms, toward their use for chiral plasmonics, quantum simulators, and control over selection rules in light–matter interactions.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- May 17, 2023
- Source ID
- 10.1364/optica.485120
Entities
People
- Eli Janzen
- Frank H. L. Koppens
- Gilles Rosolen
- Hanan Herzig Shenfux
- Ido Kaminer
- James H Edgar
- Raphael Dahan
- Yaniv Kurman
Organizations
- Agencia Estatal de Investigación
- European Research Council
- Fundación Cellex
- Generalitat of Catalonia
- Israel Science Foundation
- Kansas State University
- Office of Naval Research
- Technion – Israel Institute of Technology
- University of Mons