2023/10/18 by Maria Chiara Braidotti, M. C. Braidotti, Braidotti, M. C. +14 · 1 voice · 1 citation
Biochemistry, Genetics and Molecular Biology · Physics and Astronomy · #Classical Physics (physics.class-ph) #FOS: Physical sciences #Magnetic and Electromagnetic Effects #Mechanical and Optical Resonators #Quantum and Classical Electrodynamics #physics.class-ph
paper · pdf · doi:10.48550/arxiv.2310.12191
openalex publication_date 2023/10/18 · arxiv published 2023/10/18 · arxiv updated 2023/10/18 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/04
In 1971, Zel'dovich predicted the amplification of electromagnetic (EM) waves scattered by a rotating metallic cylinder, gaining mechanical rotational energy from the body. Since then, this phenomenon has been believed to be unobservable with electromagnetic fields due to technological difficulties in meeting the condition of amplification, that is, the cylinder must rotate faster than the frequency of the incoming radiation. Here, we show that this key piece of fundamental physics has been hiding in plain sight for the past 60 years in the physics of induction generators. 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 waves. These results reveal the connection between the concept of induction generators and the physics of this fundamental effect that was believed to be unobservable, and hence open new prospects towards testing the Zel'dovich mechanism in the quantum regime, as well as related quantum friction effects.