J. Seke

Exact Equations of Motion and Numerical Results for Two-atom Spontaneous Emission in a Damped Cavity

By using a new technique developed recently, exact closed equations of motion for expectation values for the spontaneous emission from two two-level atoms in a resonant damped cavity are derived. These equations are solved numerically for different values of the cavity damping. Moreover, different atom and field fluctuations are calculated numerically. A comparison is made with results obtained by Bonifacio, Schwendimann and Haake in the case of strong damping.

Cavity-damping effects in the interaction of a three-level atom with a single-mode radiation field

Abstract The influence of cavity damping in the interaction of a three-level atom with a single-mode radiation field is investigated. Closed equations of motion are derived for arbitrary cavity damping. Numerical results show the appearance of quasistationary occupation probabilities of the atomic levels which is a consequence of the cavity damping.

Collapse and revival phenomena in the many-atom-jaynes-cummings model in the presence on initial fock- and coherent-state fields

Abstract New aspects of cooperative radiation inhibition effects appearing in the interaction of many two-level atoms with a resonant single-mode radiation field inside a lossless cavity are examined. It is shown that collapses and revivals of the envelopes of Rabi oscillations of atomic energy expectation value occur in the presence of initial strong Fock-state fields. In the case of initial coherent fields, a cooperative energy shift of the quasi-stationary energy expectation value is pointed out. Further it is found that all cooperative radiation effects are caused by strong atom-atom correlations.

Modified Robertson projection technique in nonequilibrium statistical mechanics

SummaryThe Robertson projection technique is modified in order to eliminate the Lagrange multipliers from the equations of motion for expectation values in the case of special initial conditions. The method is illustrated by a simple example.

Exact solution of the single-atom spontaneous emission in a resonant cavity

SummaryBy using a new method an exact solution of the single-atom spontaneous emission in a resonant cavity is derived. The obtained results are compared with the results obtained from the Bonifacio-Schwendimann-Haake master equation.

The influence of the counter-rotating terms on the superradiant emission

SummaryAgarwal’s master equation for the Dicke model is modified, by including the counter-rotating terms. By solving the corresponding equations of motion for the atomic expectation values, it is shown that the counter-rotating terms play an important role in the time evolution of the population inversion and radiation rate.

Two-atom spontaneous emission in a detuned damped cavity

By using a new technique developed recently exact closed equations of motion for expectation values for spontaneous emission from two two-level atoms in a detuned damped cavity are derived. These equations are solved numerically for different values of the cavity damping and detuning. It is pointed out that the spontaneous emission is inhibited if the cavity is detuned. Moreover, by comparing the result of the single-atom case with that of the two-atom case it is shown that the collective effects can be suppressed by changing the cavity damping and detuning.

Complete solution of the free-space spontaneous emission problem in non-relativistic quantum electrodynamics

Abstract By applying a self-consistent projection-operator method, developed recently by the author, a complete treatment of the sixty- year-old problem of spontaneously decaying atomic state is achieved. In a new physical interaction picture (in which, without using the mass-renormalization concept, the unobservable interaction of the free electron with the vacuum radiation field is eliminated), by removing the shortcomings of the Weisskopf-Wigner method and taking into account virtual transition effects, explicit finite analytic results for the non-markovian time evolution in the case of Lyman-α spontaneous emission are obtained.

Stationary lineshape of a two-level atom in a narrow-bandwidth squeezed vacuum

The stationary lineshape of a two-level atom driven by low-intensity narrow-bandwidth squeezed light is shown to exhibit significant differences in behaviour compared to the lineshape for broadband squeezed light. We find that for narrow-bandwidth squeezed light the lineshape is composed of two Lorentzians whose amplitudes depend on the squeezing correlations. Moreover, one of the Lorentzians has a negative weight which leads to narrowing of the line. These features are absent in the broadband case, where the stationary lineshape is the same as for a thermal field.

Exact Equations of Motion for Density-matrix Elements and Numerical Results for Many-atom Spontaneous Emission in a Damped Cavity

Abstract An exact closed set of first-order linear differential equations for density-matrix elements, expressible in terms of a simple recurrence equation, is derived. This recurrence equation makes possible numerical calculations for a larger number N of atoms and arbitrary cavity damping in the case of spontaneous emission. For the first time, numerical results are presented for N = 3 10 and 18 in the case of high-Q cavities. A comparison with the approximate calculations of Bonifacio et al. is also given for low-Q cavities.