  Highly confined surface waves present unique opportunities to enhance light
interactions with localized emitters or molecules. Hyperbolic dispersion in
metasurfaces allows us to tailor and manipulate surface waves, enhancing the
local density of states over broad bandwidths. So far, propagation on this
platform was mainly studied in planar geometries, which facilitates the
analysis but somehow limits the realm of possibilities. Here we show that
"wrapping" hyperbolic metasurfaces into tubes may greatly enrich the wave
propagation dynamics along their axis. This system shows strong interaction
with fields and sources carrying optical angular momentum, pronounced field
asymmetries, and opens pathways to valley-specific excitation and routing. In
addition, we demonstrate that various parameter regimes enable strong spin and
helicity to momentum locking.
