Giant Acoustic Geometric Spin and Orbital Hall Effect

TL;DR

This paper presents the first theoretical and experimental demonstration of a giant acoustic geometric spin and orbital Hall effect, revealing large transverse shifts in vortex beams observed from tilted frames, enhancing understanding of wave angular momentum.

Contribution

It introduces a novel mechanism for observing giant acoustic spin and orbital Hall effects without wave-interface interactions, using tilted reference frames and beam binding.

Findings

Large transverse shifts proportional to angular momentum observed

Effect occurs in a compact system without wave-interface interactions

Mechanism enables amplification of the Hall effect in acoustic waves

Abstract

Acoustic waves in fluid with spin-0 nature have been long believed not to support spin Hall effect and strong orbital Hall effect that enables experimental observation. Here we report the first theoretical explication and experimental demonstration of giant acoustic geometric spin and orbital Hall effect characterized by a large transverse shift. We reveal that this effect occurs when a vortex beam is observed from a tilted reference frame free of wave-interface interactions or gradient-index media needed for observing conventional ones, and can be amplified by simply binding the beam tightly. Thanks to this mechanism, large transverse shifts proportional to angular momentum are observed in a compact system. Our work provides deeper insights into the physics of angular momentum of classic waves.