Low-loss diamagnetic levitation of dielectrics for sensing

Macroscopic systems, when governed by nonlinear interactions, can display rich behavior from persistent oscillations to signatures of ergodicity breaking. Nonlinearity, long regarded as a nuisance in precision systems, is increasingly recognized as a gateway to new physical regimes. While such dynamics have been extensively studied in optics and atomic physics, macroscopic systems are rarely associated with long-lived coherence and nonlinear control and remain an untapped platform for probing the fundamental nonlinear processes. Here, we report the observation of long-lived oscillatory dynamics in millimeter-scale, levitated dielectric quartz particles exhibiting decay rates as low as 4 micro Hz. The magnetic trap is constructed from a static arrangement of permanent magnets, requiring no external power or active feedback. We estimate an intrinsic acceleration sensitivity of 87 pg/sqrt(Hz). We also observe clear signatures of nonlinear mode coupling, a positive largest Lyapunov exponent of 0.0095, and partial energy recurrences—phenomena strongly reminiscent of the Fermi–Pasta–Ulam–Tsingou physics.