One-Loop Dominance in the Imaginary Part of the Polarizability: Application to Blackbody and Noncontact Van Der Waals Friction

Phenomenologically important quantum dissipative processes include blackbody friction (an atom absorbs counterpropagating blueshifted photons and spontaneously emits them in all directions, losing kinetic energy) and noncontact van der Waals friction (in the vicinity of a dielectric surface, the mirror charges of the constituent particles inside the surface experience drag, slowing the atom). The theoretical predictions for these processes are modified upon a rigorous quantum electrodynamic treatment, which shows that the one-loop correction yields the dominant contribution to the off-resonant, gauge-invariant, imaginary part of the atom\u27s polarizability at room temperature, for typical atom-surface interactions. The tree-level contribution to the polarizability dominates at high temperature