Quantum friction on a rotating pair of atomic oscillators at all temperatures and all distances
Phys. Rev. A 113, 022804 – Published 6 February, 2026
DOI: https://doi.org/10.1103/4743-z57v
Abstract
Vacuum fluctuations are known to be responsible for dispersion attraction forces, and in more general and dynamical approaches, for friction forces. In this paper, we study a system of two neutral atomic oscillators, rotating around each other, and calculate friction forces linear in their angular velocity. This system requires a precise and complete understanding of the radiation reaction effect, both on the dipolar dynamics and on the atomic center of mass. We treat the nonretarded (short range) and retarded (long range) regimes at zero or finite temperature. At very long distances, the individual thermal friction, known since the work of Einstein and Hopf, is retrieved as the dominant contribution. The model also allows for a calculation of the attractive forces in the above regimes as presented in a companion paper. The two main results are the nontrivial absence of linear friction at zero temperature, at any distance range, as long as the dipolar approximation holds, and a new, thermally activated interatomic dissipation.
