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

TL;DR

This paper demonstrates long-term stabilization of a levitated quartz rotor through nonlinear mode interactions and optical driving, revealing new multimode dynamics and potential for advanced sensors.

Contribution

It introduces the observation of nonlinear mode-crossing dissipation and injection-locking-like stabilization in a levitated rotor, a novel regime of multimode nonlinear dynamics.

Findings

Rotational dissipation times of several days.

Discrete steps in angular velocity during mode crossings.

Stable rotation maintained for about two days with weak torque.

Abstract

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.