• JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
 
  Bookmark and Share
 
 
Doctoral Thesis
DOI
10.11606/T.43.2000.tde-02122013-185457
Document
Author
Full name
Sonia Geraij Mokarzel
Institute/School/College
Knowledge Area
Date of Defense
Published
São Paulo, 2000
Supervisor
Committee
Nemes, Maria Carolina (President)
Escobar, Carlos Ourivio
Mizrahi, Salomon Sylvain
Piza, Antonio Fernando Ribeiro de Toledo
Zagury, Nicim
Title in Portuguese
Decoerência e Dissipação de Sistemas Quânticos: Técnicas e Aplicações
Keywords in Portuguese
Mecânica estatística
Mecânica quântica
Abstract in Portuguese
Desenvolvemos no presente trabalho um tratamento perturbativo para a matriz densidade reduzida de forma similar à regra áurea de Fermi para espalhamento. Aplicamos a teoria a vários exemplos e em particular reproduzimos os resultados experimentais obtidos no laboratório Kastler Brossel e obtivemos uma relação entre os tempos característicos de dissipação e decoerência. Por outro lado, desenvolvemos um modelo simples para duas moléculas interagindo com um reservatório. Mostramos resultados surpreendentes quando temos mais que dois subsistemas interagindo: no caso particular em que as moléculas estão num estado inicial coerente, bombardeadas por fontes de mesma intensidade, o estado assintótico apresenta urna concentração de energia no modo de menor frequência. Este resultado dá suporte a um modelo fenomenológico de sistemas biológicos onde a condensação de Bose- Einstein é produzida e o estado final também exibe uma concentração de energia no modo de frequência mais baixa.
Title in English
Decoherence and dissipation in quantum systems: techniques and applications.
Keywords in English
Quantum mechanics
Statistical mechanics
Abstract in English
In the present work we developed a perturbative treatment of reduced density matrices which is similar in spirit to Fermi's Golden Rule for scattering. We applied the theory to several e- xamples and in particular reproduced the results obtained in the laboratory Kastler Brossel experiment quantifying the relation between decoherence and dissipation characteristic times. On the other hand we developed a simple model for two molecules interacting through a re- servoir. We show that rather surprising results may arise when we have more than two subsys- tems in interaction: in the particular case where both molecules are initially in coherent states, if they are pumped with the same strength, the asymptotic state shows a concentraction of energy on the mode with smallest frequency. This result gives support to a phenomenological model for biological systems where a Bose- Einstein condensation is predicted and the final state also exhibits a concentration of energy in the lowest frequency mode.
 
WARNING - Viewing this document is conditioned on your acceptance of the following terms of use:
This document is only for private use for research and teaching activities. Reproduction for commercial use is forbidden. This rights cover the whole data about this document as well as its contents. Any uses or copies of this document in whole or in part must include the author's name.
Publishing Date
2014-02-21
 
WARNING: Learn what derived works are clicking here.
All rights of the thesis/dissertation are from the authors
Centro de Informática de São Carlos
Digital Library of Theses and Dissertations of USP. Copyright © 2001-2022. All rights reserved.