  Proposing a system of two rotatable nanoparticles (NPs) in the presence of
electromagnetic vacuum fluctuations, using the framework of canonical
quantization, the electromagnetic and matter fields have been quantized. The
non-contact frictional torque, affecting the rotation of NPs due to the
presence of electromagnetic vacuum fluctuations and also by the matter field
fluctuations have been derived. Considering the distance between NPs less than
100 nm in the near-field, we observe the rotations are phase locked. It has
been shown that the electromagnetic vacuum fluctuations play the role of noises
to break down the synchronization. Also surprisingly, we find the frictional
torque between NPs in the near-field is much bigger than the popular contact
friction between them where it causes a robust synchronization in the
near-field.

Quantum Physics;Mesoscale and Nanoscale Physics