TY - JOUR
T1 - Dynamics of optical vortices in van der Waals materials
AU - Kurman, Yaniv
AU - Dahan, Raphael
AU - Shenfux, Hanan Herzig
AU - Rosolen, Gilles
AU - Janzen, Eli
AU - Edgar, James H.
AU - Koppens, Frank H.L.
AU - Kaminer, Ido
N1 - Publisher Copyright: © 2023 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement.
PY - 2023/5/20
Y1 - 2023/5/20
N2 - 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.
AB - 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.
UR - http://www.scopus.com/inward/record.url?scp=85163375955&partnerID=8YFLogxK
U2 - https://doi.org/10.1364/OPTICA.485120
DO - https://doi.org/10.1364/OPTICA.485120
M3 - مقالة
SN - 2334-2536
VL - 10
SP - 612
EP - 618
JO - Optica
JF - Optica
IS - 5
ER -