Louis Bellando
Laboratoire Ondes et Matière d’Aquitaine, Université de Bordeaux

“Rotational dynamics of trapped nano-objects in vacuum”

Optical tweezers offer a huge amount of opportunities going from fundamental physics (as e.g. test of quantum mechanics) to applied science such as precision metrology or biophysics.
Recently, a growing interest in levitated otpomechanics platforms is to investigate the rotational degrees of freedom. Under a circularly polarized laser beam, the particle has shown the fastest spin (above ~GHz) for a man-made object. Surprisingly, the mechanism behind the origin of spin for a nanosphere remains elusive.
In this talk, after a general presentation about optical trapping, I will present some recent results concerning the optically induced rotation of trapped nano-objects and show that above a certain critical range of pressures and ellipticity competition between spin and torque dynamics occurs. This novel observation is expected to bring new insights into the understanding of the different mechanisms taking place in the rotational dynamics of a trapped sphere.