  We present a classical version of several quantum bit (qubit) functionalities
using a two-component magnon Bose-Einstein condensate formed at opposite
wavevectors in a room-temperature yttrium-iron-garnet ferrimagnetic film. The
macroscopic wavefunctions of these two condensates serve as orthonormal basis
states that form a system being a classical counterpart of a single qubit.
Solving the Gross-Pitaevskii equation and employing micromagnetic numerical
simulations, we first show how to initialize the system in one of the basis
states: the application of wavevector-selective parallel parametric pumping
allows us to form only a single condensate in one of the two lowest energy
states of the magnon gas. Next, by translating the concept of Rabi-oscillations
into the wavevector domain, we demonstrate how to manipulate the magnon-BEC
system along the polar axis in the Bloch sphere representation. We also discuss
the manipulation regarding the azimuthal angle.
