There’s no such thing as silicon nanotubes, as fas as I know.
My theory postulates that in these lattice environments a Luttinger Liquid Linear Bose-Einstein Condensate is formed.
These latest rounds of theories proposing Metallic Hydrogen serving as the host lattice are extensions of the Luttinger Liquid model, in essence they’re momentary Linear Luttinger Solids [generating a linear BEC].
https://en.wikipedia.org/wiki/Silicon_nanotube