Meissner-levitated microrotor reaches 2.3 MHz in cryogenic vacuum experiment
Physicists demonstrated a magnetically levitated microsphere spinning at 2.3 MHz with ultra-low damping at 4.2 kelvin.
Researchers demonstrated a Meissner-levitated microrotor reaching rotation speeds above 2.3 megahertz at a cryogenic temperature of 4.2 kelvin, according to a report published in Science Advances science.org
Science Advancesscience.orgOpen source ↗. The experimental platform uses a magnetic microsphere suspended via the Meissner effect. The system achieved a mechanical damping rate of 4.75 × 10 −7 hertz, enabling high-precision measurements in an ultra-low-noise regime.
By leveraging the linear dependence of friction on gas density, the authors demonstrated high-accuracy absolute cryogenic pressure sensing across a wide operating range. Additionally, operating the microrotor in a synchronized mode at intermediate gas pressure allowed the team to measure thermal torque noise. This sensitivity enabled a preliminary narrowband search for axion-like dark matter.
The authors noted that combining high rotational velocity, cryogenic operating temperatures, and low thermal torque noise provides a platform for measuring extremely weak forces and fields.
