Levitated milligram-scale ferromagnetic magnetometer at room temperature
Phys. Rev. Applied 25, 024090 – Published 27 February, 2026
DOI: https://doi.org/10.1103/fnhb-bzqr
Abstract
Levitated mechanical oscillators are emerging ultrasensitive sensors with tremendous potential in both applied and fundamental physics. Levitated ferromagnets, with internal spin noises rapidly averaged, promise ultrahigh magnetic sensitivity. Here, we demonstrate a milligram-scale diamagnetically levitated ferromagnet system operating at room temperature. Through optimized geometry and multichannel dissipation control, we achieve a magnetic sensitivity of at the 100-Hz frequency level. We anticipate that a ferromagnetic magnetometer with subfemtotesla sensitivity is within reach, after modest technical improvements. This platform establishes a high-performance magnetometer for biomagnetic field detection and beyond-standard-model force searches.
