  Twisted magnons (TMs) carrying orbital angular momentum (OAM) have attracted
much attention from the magnonic community. The fabrication of such novel
magnon state however is still challenging. Here we present a simple method to
generate TMs with arbitrary radial and azimuthal quantum numbers through the
spin-to-orbital angular momentum conversion. The conversion rate from
plane-wave magnons to twisted ones is shown to be insensitive to the quantum
index. The spectrum of TMs in thin nanodisks is solved analytically, showing a
good agreement with micromagnetic simulations. Moreover, we numerically study
the propagation of TMs in magnetic nanodisk arrays and obtain the quantitative
dependence of the decay length on quantum indexes. Our results are helpful for
realizing TMs with large OAMs that are indispensable for future high-capacity
magnonic communications and computings.
