Phys.org April 8, 2024
An international team of researchers (Japan, Taiwan, Mexico, Australia) demonstrated the passive, diamagnetic levitation of a centimeter-sized massive oscillator, which was fabricated ensuring that the material, though highly diamagnetic, was an electrical insulator. By chemically coating a powder of microscopic graphite beads with silica and embedding the coated powder in high-vacuum compatible wax, they formed a centimeter-sized thin square plate which magnetically levitated over a checkerboard magnet array. The insulating coating reduced eddy damping by almost an order of magnitude compared to uncoated graphite with the same particle size. The plates exhibited a different equilibrium orientation from pyrolytic graphite. They measured motional quality factor for an approximately centimeter-sized composite resonator with a mean particle size of 12 μm. They applied delayed feedback to cool the vertical motion of frequency and achieved center-of-mass temperature decrease of three orders of magnitude… read more. Open Access TECHNICAL ARTICLE
Coated graphite and experimental setup… Credit: Appl. Phys. Lett. 124, 124002, 2024