Quantum mechanics

Detector

Magnetic field

Rotor (electric)

Quantum noise

Pure mathematics

Radiation pressure

Radiation

Laser cooling

Rotation around a fixed axis

Field (mathematics)

Atomic physics

Shot noise

Computer science

Classical mechanics

Rotation (mathematics)

Optomechanics

Laser

Physics

Torque

Mathematics

Optics

Image (mathematics)

Angular momentum

Work (physics)

Artificial intelligence

Geometry

Quantum

Mechanics

Noise (video)

Physical Review Letters

Rotational optomechanics strives to gain quantum control over mechanical rotors by harnessing the interaction of light and matter. We optically trap a dielectric nanodumbbell in a linearly polarized laser field, where the dumbbell represents a nanomechanical librator. Using measurement-based parametric feedback control in high vacuum, we cool this librator from room temperature to 240 mK and investigate its heating dynamics when released from feedback. We exclude collisions with residual gas molecules as well as classical laser noise as sources of heating. Our findings indicate that we observe the torque fluctuations arising from the zero-point fluctuations of the electromagnetic field.

Sub-Kelvin Feedback Cooling and Heating Dynamics of an Optically Levitated Librator