Classical and quantum mechanical resonance fluorescence

We study resonance fluorescence from a two-level atom illuminated by coherent and incoherent light. Especially, we treat the case of an intense incoherent component which is broad band and chaotic in character.New insights into the phenomenon of resonance fluorescence are obtained by constructing certain analogies with the precession of a classical (Bloch) vector around a classical stochastic field. The analogies are based on a representation of the density operator of the two-level atoms as a diagonal mixture of directed angular momentum states.As long as the whole light field is an imposed one the weight function of the mixture mentioned above describes a random sequence of rotations of the Bloch vector and obeys a simple Fokker Planck equation. If, however, the incoherent component of the light field acts as a zero- or finite temperature heat bath, the equation of motion for the weight function is no longer a Fokker Planck equation. Nontheless, we find the exact solution and calculate the correlation functions relevant to a discussion of the spectrum and of antibunching effects.     

Untersuchungen an Salzhydraten. IV. Thermische Zersetzung der Lithiumhalogenidkristallhydrate

Studies on Salt Hydrates. IV. Thermal Decomposition of Lithiumhalide Hydrates The thermal decomposition of LiX · nH₂O and LiX · nD₂O (X = Cl, Br, I; n = 1, 2, 3) is investigated on a thermobalance. There are differences in the stages of degradation depending on the starting hydrates and the anion radius. The thermal stability decreases with increasing quantity of water. Deuterates are of higher stability as hydrates.     

Stochastic dynamics of two-dimensional infinite-particle systems

The time evolution of an open system of infinitely many two-dimensional classical particles is investigated. Particles are interacting by a singular pair potentialU, and each particle is connected to a heat bath of temperatureT. The heat baths are represented by independent white noise forces and Langevin damping terms. Existence of strong solutions to the corresponding infinite system of stochastic differential equations is proved for initial configurations with a logarithmic order of energy fluctuations. Gibbs states forU at temperatureT are invariant under time evolution.     

Konstruktion vollständiger Minimalflächen von endlicher Gesamtkrümmung

Ohne Zusammenfassung Vorgelegt von J.C.C. Nitsche     

Bildung Siliciumorganischer Verbindungen. XXXXV. Die Synthese von 1,3,3,5,5,8,8-Heptamethyl-1,3,5,8-tetrasila-bicyclo-[2,2,2]-octan

We report the synthesis of (a), which is finally formed by the reaction of (b) with CHBr₃ and Li. (b) can be obtained from (c) by a cleavage with Br₂ and yields (d) with LiAlR₄. The synthesis of (c) is described. (a) is a very stable crystalline compound, m.p. 55–56°C.