Translational and rotational (nanothermo)-dynamics with a trapped particle

During a transformation between thermal equilibrium states, a system remains out of equilibrium for a characteristic relaxation time 𝜏_𝑟. Controlling this transient regime is crucial for optimizing power in nanoscale and biological systems. Previous work demonstrated state-to-state transformations faster than 𝜏_𝑟 for an overdamped Brownian particle. We extended these shortcuts to the underdamped regime using an optically levitated particle in moderate vacuum. Leveraging the system’s 3D nature, we assess protocol robustness across trap axes, relevant for multimode systems. This advances optimal state-to-state transformations, with applications to nano-heat engine efficiency. We then investigate coupling between rotational and translational degrees of freedom, studying viscous dissipation in liquids with microscopic vaterite particles. In vacuum, we present the subtle nonsymmetric coupling between these degrees of freedom, leading to coherent oscillations with ultranarrow linewidth.