Quantum electrodynamics of an atom in front of a non-dispersive dielectrichalf-space II. Effects of finite temperature

The energy-level shifts of all atom located at a distance Z outside a diele ctric halfspace are calculated at finite temperatures. The refractive index of the medium is real and frequency independent; the limiting case of perf ect reflectors is also considered. The analytic expressions for the energy- level shifts are analysed in various regimes of temperature and of the dist ance of the atom from the surface. The significance of thermal corrections in comparison with zero-temperature effects is analysed in each regime and discussed for recent experiments.