Diamagnetically levitating diamond resonator

Abstract

Diamagnetic levitation offers a contactless, room-temperature platform for creating high-quality mechanical resonators. This study investigates the dynamic behavior of levitated diamond particles as potential high Q resonators. Using a cone shaped pole-piece magnet assembly, we achieve stable levitation of single crystalline diamond particles and clusters up to 400 μm in diameter. By leveraging diamond's extremely low electrical conductivity (∼ 10^-13 S/m), eddy current damping is nearly eliminated, leaving air resistance as the dominant dissipation mechanism. Resonant modes—including transverse, radial, and rotational—are characterized using laser Doppler vibrometry, with actuation enabled via electrostatic forces. Frequency response and Q factor measurements across a range of pressures reveal that while a Q factor up to 4250 is achieved, it remains below theoretical limits due to additional damping, likely caused by inter-particle friction and mode coupling in clusters.  Furthermore, frequency shifts with decreasing pressure suggest that ambient air contributes to effective stiffness, in addition to damping. These findings demonstrate the potential of diamond for next-generation, high Q, room-temperature levitated resonators, while highlighting the challenges posed by cluster dynamics and external perturbations.