Ultralow Mechanical Damping with Meissner-Levitated Ferromagnetic Microparticles

Levitation of magnetic or superconducting microparticles is a promising technology for applications such as ultrasensitive force and gravity sensors, and experiments in fundamental and quantum physics. Unfortunately, achieving very low dissipation has proven to be more difficult than expected. This study demonstrates levitation of micromagnets by the Meissner effect above type-I superconductors, with very long damping times beyond 10⁴ s and quality factors exceeding 10⁷. The authors furthermore investigate using a levitated micromagnet as an ultrasensitive magnetometer, pointing out the potential for magnetic-field resolution beyond the current state of the art.