Fig. 1: Schematic illustration of the experiment.
The superfluid 3He sample is contained in a quartz glass cylinder. The magnon time crystal (blue blob) is trapped in the middle of the container by the combined effect of a minimum in the static magnetic field, created using a pinch coil (green wire loop), and by the spatial distribution of the superfluid orbital momentum L (small green arrows). The coherent precession of magnetisation M (magenta cone) in the time crystal is observed using transverse pick-up coils. The static magnetic field H is oriented parallel to the axis of the cylinder. The ripple on the superfluid free surface is added for illustrational purposes. The two-level time crystal is schematically illustrated in Fig. 2.
