Requirements for coherent atom channeling
The evolution of atomic de Broglie waves inside strong periodic potentials can be described as channeling and exhibits both particle and wave effects. Using a beam of metastable Argon atoms interacting with an intense standing light wave we detect an interference pattern arising from the coherent guiding of the atoms through the light channels. In analogy to light optics these interference effects are only visible, if certain requirements for longitudinal and transverse coherence are fulfilled. We experimentally study the influence of the velocity selection and the collimation of the Argon atoms. As well as an another factor determining the coherence of the evolution - the spontaneous emission. q 2000 Elsevier Science B.V. All rights reserved.
This paper addresses the problem of traffic grooming in wavelength-division multiplexing (WDM) rings where connection requests arrive online. Each request specifies a pair of nodes that wish to communicate and also the desired bandwidth of this connection. If the request is to be satisfied, it must be allocated to one or more wavelengths with sufficient remaining capacity. We consider three distinct profit models specifying the profit associated with satisfying a connection request. We give results on offline and online algorithms for each of the three profit models. We use the paradigm of competitive analysis to theoretically analyze the quality of our online algorithms. Finally, experimental results are given to provide insight into the performance of these algorithms in practice.