Based on a microscopic approach, we propose a Lagrangian for the combined system of a rotating dielectric nanoparticle above a plane surface in the presence of electromagnetic vacuum fluctuations. In the framework of canonical quantization, the electromagnetic vacuum field is quantized in the presence of dielectric fields describing the nanoparticle and a semi-infinite dielectric with planar interface. The radiative heat power absorbed by the rotating nanoparticle is obtained and the result is in agreement with previous results when the rotational frequency ${\omega }_0$ of the nanoparticle is zero or much smaller than the relaxation frequency of the dielectrics. The well-known near-field effect is reexamined and discussed in terms of the rotational frequency. The radiative heat power absorbed by the nanoparticle for well-known peak frequencies is plotted in terms of the rotational frequency ${\omega }_0$ showing an interesting effect resembling a phase transition around a critical frequency $\mathrm{\Gamma }$, determined by the relaxation frequency of the dielectrics.

• Received 3 June 2015

DOI:https://doi.org/10.1103/PhysRevA.92.022110