An elongated object can be rotated around one of its short axes, like a propeller, or around its long axis, like a spinning top. Using optically levitated nanoparticles, short-axis rotation and libration have been systematically investigated in several recent studies. Notably, short-axis rotational degrees of freedom have been cooled to millikelvin temperatures and driven into gigahertz rotational speeds. However, controlled long-axis spinning has so far remained an unrealized goal. Here, we demonstrate controlled long-axis spinning of an optically levitated nanodumbbell with spinning rates exceeding 1 GHz. We show that the damping rate in high vacuum can be as low as a few millihertz. Our results open up applications in inertial torque sensing and studies of rotational quantum interference.

APS
The Netherlands Organisation for Scientific Research (NWO)
doi.org/10.1103/PhysRevLett.132.253601
Phys.Rev.Lett.
Photonic Forces

Zielińska, J. A., van der Laan, F., Norrman, A., Reimann, R., Frimmer, M., & Novotny, L. (2024). Long-Axis Spinning of an Optically Levitated Particle: A Levitated Spinning Top. Phys.Rev.Lett., 132(25), 253601: 1–6. doi:10.1103/PhysRevLett.132.253601