Coherent Momentum State Manipulationof Matter WavesDissertation der Fakult¨at fu¨r PhysikderLudwig-Maximilians-Universit¨at Mu¨nchenvorgelegt vonSierk P¨ottingMu¨nchen, den 01. Juni 2004i1. Gutachter: Prof. H. Walther2. Gutachter: Prof. A. SchenzleTag der mu¨ndlichen Pru¨fung: 20. Dezember 2004iiFor Tessa and our little son OskarAbstractThis dissertation presents a theoretical analysis of methods to manipulate and con-trol the momentum state of coherent matter waves. Of particular interest is thecoherent acceleration of a quantum-degenerate atomic system, which, as a directconsequence of the form of the de Broglie wavelength, results in tunable source ofmatter waves. Such sources are of considerable importance for a number of poten-tial applications in the field of atom optics, including the development of highlysensitive gyroscopes, accelerometers, gravity gradiometers or atom lithography andholography, as well as for potential uses in integrated atom optics.Our basic setup consists of a Bose-Einstein condensate in a moving optical latticecreated by a pair of frequency-chirped counterpropagating laser beams acting as a“conveyor belt” for ultracold atoms. Whereas the acceleration of ultracold but non-condensed atoms in such a lattice was demonstrated earlier, we extend this schemeto the case of Bose-Einstein condensates.As a first step, we investigate the acceleration efficiency for various accelerationrates and nonlinear interaction strengths.