Observation of gyroscopic coupling in a non-spinning levitated ferromagnet

A non-spinning permanent ferromagnet is predicted to behave as a gyroscope at sufficiently low frequencies, which can be seen as a manifestation of the Einstein-de Haas effect. This yet unexplored regime has been recently proposed for ultrasensitive precession-based magnetometry and for atomic-like quantum stabilization of a levitated nanomagnet in a static field. Here, we observe signatures of gyroscopic effects in the rotational dynamics of a non-spinning permanent ferromagnet levitated in a superconducting trap. Specifically, we detect spin-rotation coupling between different librational modes, in good agreement with theoretical predictions. From our measurements, we can infer both the intrinsic angular momentum of the levitated magnet and its gyromagnetic $g$-factor.