Observation of acoustic spin
arXiv:1808.03686 · doi:10.1093/nsr/nwz059
Abstract
Unlike optical waves, acoustic waves in fluids are described by scalar pressure fields, and therefore are considered spinless. Here, we demonstrate experimentally the existence of spin in acoustics. In the interference of two acoustic waves propagating perpendicularly to each other, we observed the spin angular momentum in free space as a result of the rotation of local particle velocity. We successfully measured the acoustic spin, and spin induced torque acting on a lossy acoustic meta-atom that results from absorption of the spin angular momentum. The acoustic spin is also observed in the evanescent field of a guided mode traveling along a metamaterial waveguide. We found spin-momentum locking in acoustic waves whose propagation direction is determined by the sign of spin. The observed acoustic spin could open a new door in acoustics and their applications for the control of wave propagation and particle rotation.
arXiv comment17 pages, 3 Figures
References in corpus (13)
- Spin-orbit interactions of light
- Chiral Quantum Optics
- Acoustic topological insulator and robust one-way sound transport
- Transverse and longitudinal angular momenta of light
- Quantum spin Hall effect of light
- Chiral nanophotonic waveguide interface based on spin-orbit coupling of light
- Extraordinary momentum and spin in evanescent waves
- Deterministic photon-emitter coupling in chiral photonic circuits
- All-Optical Routing of Single Photons by a One-Atom Switch Controlled by a Single Photon
- Valley Vortex States in Sonic Crystals
- Quantum optical circulator controlled by a single chirally coupled atom
- Rotational Quantum Friction
- Extraction of a single photon from an optical pulse
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- Harnessing curvature for helical wave generation in spiral-based metamaterial structures