Fluctuations in quantum optical systems [Elektronische Ressource] : from Bose-Einstein condensates to squeezed states of light / von Alem Mebrahtu Tesfamariam

FluctuationsinQuantum Optical Systems:FromBose-Einstein CondensatestoSqueezed States of LightVon der Fakultat fur Mathematik und Physik derGottfried Wilhelm Leibniz Universitat Hannoverzur Erlangung des GradesDoktor der NaturwissenschaftenDr. rer. nat.genehmigteDissertationvonAlem Mebrahtu Tesfamariam2006iiiReferent: Prof. Dr. Maciej LewensteinKorreferent: Prof. Dr. Luis SantosTag der Promotion: 26.10.2006AbstractIn this Thesis we study the theory of uctuations in quantum optical sys-tems: from Bose-Einstein condensates to squeezed states of light. The Thesisis divided into three parts, which, although dealing with di eren t areas ofquantum optics have a joint aspect in that they concern uctuations.In the rst part we consider the problem of evaporative cooling of anatomic gas towards high phase space densities. Thermal uctuations insuch a gas may be very well described by classical Monte Carlo methodsand molecular dynamics. Nevertheless, the described process of evaporativecooling leads to the realization of a quantum degenerate regime. Applyingmolecular dynamics simulation we study the dynamics of evaporative cool-87ing of cold gaseous Rb atoms in an anisotropic trap loaded continuouslyfrom an incoming atomic beam. Based on this simulation, we show that it8is possible to continuously trap more than 10 atoms with a relatively highphase space density exceeding 0.011 at an equilibrium temperature of nearly20 K.