The stationary states of several atomic systems

Michael G. Raymer

The fi rst postulate enunciates the existence of stationary states of an atomic system. The second postulate states that the transition of the system from one stationary state to another is … accompanied by the emission of one quantum of … radiation.

Herbert Stanley Allen

D. Dubbers, H.‐J. Stöckmann

V. M. Arutyunyan, A. Zh. Muradyan

We investigate possible stationary states of a system consisting of a motionless atom in the resonant field of quantized isofrequency counterpropagating waves. Spontaneous relaxation is ignored. In the initial state (in the absence of an interaction), the photon subsystem has definite numbers of photons in each wave. We obtain analytic expressions for the energy spectrum and wave functions of this system. In particular, we show that the system can be in a stationary state only when the average numbers of photons in the counterpropagating waves are equal. We estimate the time it takes a system with an arbitrary initial number of photons in the counterpropagating waves to make a transition to a stationary state with equal numbers of photons in the waves.

Tapan Kumar Das

M.S. Rogalski, Stuart B. Palmer

The states of the atom, determined by the motion of electrons, are stationary in the presence of all internal atomic forces and of interactions with constant external fields. When electrons interact with the field associated with electromagnetic radiation, the atomic states are no longer stationary, and the time-dependent perturbation treatment has to be applied to calculate the effect produced by the radiation, which is a function of time. Consequently, as shown in Section 9.3 , the time evolution of the atom will be described in terms of transitions between the stationary states of the unperturbed atomic system.