Mehrdad M. Sourki | Searcharxiv

arXiv2026

Driven Dissipation and Stabilization of a Levitated Rotor with Multi-Day Coherence

We report the experimental observation of nonlinear mode-crossing dissipation and injection-locking-like stabilization in a milligram-scale diamagnetically levitated quartz cube. By optically driving the cube to rotation rate near 360 RPM, we observe that its angular velocity does not decay smoothly but instead decreases in discrete steps whenever the instantaneous rotation frequency crosses one of several higher-order mechanical modes. We observe rotational dissipation times on the order of a few days. When a weak counteracting radiation-pressure torque is applied, the system unexpectedly stabilizes at a constant rotation rate that persists for about two days, constituting the mechanical analogue of injection locking. Our results reveal a new regime of multimode nonlinear dynamics in low-dissipation levitated solids and establish diamagnetic levitation as a platform for exploring non-Hamiltonian many-mode interactions and mechanically engineered nonlinear attractors and sensors.

physics.app-ph↗

arXiv2025

Nonlinear Dynamics and Fermi-Pasta-Ulam-Tsingou Recurrences in Macroscopic Ultra-low Loss Levitation

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 clear signatures of nonlinear mode coupling, a positive largest Lyapunov exponent of 0.0095 s^-1, and partial energy recurrences-phenomena strongly reminiscent of the Fermi-Pasta-Ulam-Tsingou physics. We observe dissipation rates below 4*10E-6 Hz, limited by our ability to measure dissipation in presence of nonlinear dynamics. We estimate an intrinsic acceleration sensitivity of 62*10E-12 g/sqrt(Hz), at room temperature. The magnetic trap is constructed from a static arrangement of permanent magnets, requiring no external power or active feedback. Our findings open a path toward leveraging nonlinear dynamics for novel applications in sensing, signal processing, and statistical mechanics.

physics.app-ph↗