This paper explains it guys: “spinning shafts (or discs) in the presence of an oscillating magnetic field at matching frequencies (and higher) pulls energy from the quantum vacuum and amplifies original field. This is known as the Zel’dovich effect and it’s just been proven ”

Here, we measure the amplification of an electromagnetic field, generated by a toroid LC-circuit, scattered by an aluminium cylinder spinning in the toroid gap. We show that when the Zel’dovich condition is met, the resistance induced by the cylinder becomes negative implying amplification of the incoming EM fields.

…These findings open the way to the merging of ideas from two previously disconnected fields. In particular, a suggestive prospect is the realisation of Zel’dovich electromagnetic amplification from a rotating body in the quantum regime5,22, i.e., the generation of photons out of the quantum vacuum stimulated by a mechanical rotation