Noise-driven phenomena on the dynamics of levitated nanoparticles

Micro and nanoparticles can be individually manipulated by different trapping mechanisms, among which optical tweezers and Paul traps are the most extended approaches. Trapped particles are subject to Brownian motion, due to collisions with water or gas molecules, depending on the dispersing medium. Once trapped, the particles can be driven out of equilibrium under the action of external fields, giving rise to very rich dynamics. In this talk, we will discuss some of our work with trapped nanoparticles dispersed in different media, including water, air, and vacuum. We will show that exquisite control over the dynamics can be achieved by using state-of-the-art instrumentation, thanks to the sensitivity over position and forces that these provide. Our most recent results are related to the observation of the Kovacs effect on the energy of a levitated nanoparticle, a memory effect first observed in polymers. According to this effect, the thermalization of a nanoparticle can follow a non-monotonic path due to the inertia of the system.