Electronic conduction in linear quantum systems [Elektronische Ressource] : coherent transport and the effects of decoherence / von Matías Zilly

Electronic conduction in linear quantum systems:Coherent transport and the effects of decoherenceVon der Fakultat fur Physik¨ ¨der Universitat Duisburg-Essen¨zur Erlangung des GradesDr. rer. nat.genehmigte DissertationvonMat´ıas Zillyaus Mulheim an der Ruhr¨Tag der Disputation: 16.04.2010Referent: Prof. Dr. Dietrich E. WolfKorreferent: Prof. Dr. Juan Carlos CuevasFur¨ Mar´ıa Bel´enAbstract. Coherent quantum transport in linear and quasi-linear tight-binding mod-els and the influence of decoherence are studied. For the coherent transport descrip-tion, Green functions and surface Green functions of semi-infinite systems are calcu-lated and the transmission through defects and finite tight-binding chains with and with-out diagonal disorder are examined. A statistical model based on the division of alarge system into coherent subsystems and decoherence regions is analyzed. While onthe total system level, classical rate equations interrelate electron energy distributionfunctions assigned to the decoherence regions, the transition rates themselves are cal-culated using quantum transport formalism. Thus a two-scale approach is used. Forcontact Fermi energies within the tight-binding band of the system without disorder,ohmic large scale behavior is observed for any finite density of decoherence regions. Ifthe Fermi energy is outside the band, and for disordered systems, critical decoherencedensities are defined.