NUMERICAL-SIMULATION OF FUNDAMENTAL PROCESSES IN 1-D CAVITY QED - POSITION-DEPENDENCE OF SPONTANEOUS DECAY OF 2-LEVEL ATOMS

We present results for numerical simulations of the spontaneous decay of one and two two-level atoms interacting with a multimode cavity fie ld. We describe the interaction between the atoms and the cavity field within the dipole and the rotating-wave approximations. To simplify t he model, we ignore all the mechanical effects of the cavity vacuum fi elds on the atom (i.e., the mass of the atom is assumed to be infinite ). We show that in the case of a sufficient number of discrete cavity modes, the initially excited atom spontaneously decays into its lower state, provided the atom is positioned around the center of the cavity . To be specific, minor variations in the position of the atom around the center of the cavity do not affect the exponential (or more precis ely, quasi-exponential) character of the decay (providing the cavity i s large enough). On the other hand, we show that Poincare recurrences (i.e., re-excitations of the atom by radiation reflected by the cavity mirrors) are very sensitive to the position of the atom inside the ca vity. Therefore, variation of the position of the atom within the wave length of the resonant atomic frequency can result in almost complete suppression of the first Poincare recurrence of the excited level of t he atom; that is the atom effectively does not ''see'' cavity mirrors for times much longer than the Lie (i.e., times necessary for emitted light to travel to the mirrors and back to the atom). We also investig ate the inhibition of spontaneous emissions when the atom is placed cl ose to the atomic mirrors. Finally, we analyze super-radiation and sub -radiation from a pair of atoms inside the cavity.