Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Spin-orbit interactions of transverse sound   Spin-orbit interactions (SOIs) endow light with intriguing properties and
applications such as photonic spin-Hall effects and spin-dependent vortex
generations. However, it is counterintuitive that SOIs can exist for sound,
which is a longitudinal wave that carries no intrinsic spin. Here, we
theoretically and experimentally demonstrate that airborne sound can possess
artificial transversality in an acoustic micropolar metamaterial and thus carry
both spin and orbital angular momentum. This enables the realization of
acoustic SOIs with rich phenomena beyond those in conventional acoustic
systems. We demonstrate that acoustic activity of the metamaterial can induce
coupling between the spin and linear crystal momentum k, which leads to
negative refraction of the transverse sound. In addition, we show that the
scattering of the transverse sound by a dipole particle can generate
spin-dependent acoustic vortices via the geometric phase effect. The acoustic
SOIs can provide new perspectives and functionalities for sound manipulations
beyond the conventional scalar degree of freedom and may open an avenue to the
development of spin-orbit acoustics.

13
The categories of this paper are: quant-ph
20
The categories of this paper are: acc-phys
31
The categories of this paper are: ao-sci
0
The categories of this paper are: hep-ph
9
The categories of this paper are: nlin
37
The categories of this paper are: supr-con
8
The categories of this paper are: hep-ex
18
The categories of this paper are: econ
1
The categories of this paper are: cs
33
The categories of this paper are: plasm-ph
12
The categories of this paper are: nucl-th
35
The categories of this paper are: mtrl-th
6
The categories of this paper are: astro-ph
27
The categories of this paper are: comp-gas
19
The categories of this paper are: eess
2
The categories of this paper are: math