Rotational synchronization of two noncontact nanoparticles

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 noncontact frictional torque, which affects the rotation of NPs due to the presence of electromagnetic vacuum fluctuations and also due to the matter field fluctuations, has been derived. Considering a distance between NPs of less than 100 nm in the near field, we observe that the rotations are phase locked. It has been shown that electromagnetic vacuum fluctuation plays the role of noise that breaks down the synchronization. Also, surprisingly, we find that the frictional torque between NPs in the near field is much bigger than the popular contact friction between them, where it causes robust synchronization in the near field. (C) 2017 Optical Society of America