2026/07/24 by Xianfeng Chen, Nirmala Raj, Matthew R. Chua +7
#cond-mat.mes-hall #physics.app-ph
Levitated systems and high-Q membrane nanomechanical resonators have achieved exceptional sensitivity in precision sensing, but functionalizing such resonators for practical applications without degrading their low dissipation remains challenging. Here, we combine diamagnetic levitation with a high-Q nanomechanical resonator to realize a high-precision magnetometer for sensing weak oscillating magnetic fields. A macroscopic diamagnetically levitated graphite plate acts as a free-floating proof mass that couples strongly to magnetic fields, converting them into mechanical motion that is resonantly amplified by a low-dissipation nano-trampoline resonator. Operating at room temperature and without magnetic shielding, we achieve a peak magnetic-field sensitivity of 4.5 pT/√(Hz) using a resonator with a mechanical quality factor of Q=6×106 at 443 kHz. The system sensitivity is limited by thermomechanical noise. With further improvements in mechanical Q, this hybrid levitated platform offers a pathway toward femtotesla-level AC magnetic-field sensing, establishing diamagnetically levitated nanomechanical resonators as a new class of high-sensitivity magnetometers at room temperature.