Decoherence: Theoretical, Experimental, and Conceptual Problems: Proceeding of a Workshop Held at Bielefeld, Germany, 10–14 November 1998

342 Pages·2000·11.085 MB·English

by  Erich Joos (auth.), Philippe Blanchard, Erich Joos, Domenico Giulini, Clau Kiefer, Ion-Olimpiu Stamatescu (eds.)

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Ph. Blanchard D. Giulini E. Joos
C. Kiefer I.-O. Stamatescu (Eds.)
Decoherence:
Theoretical, Experimental,
and Conceptual Problems
Proceedings of a Workshop Held at Bielefeld,
Germany, 10-14 November 1998
1 3
Editors
PhilippeBlanchard ErichJoos
Fakulta¨tfu¨rPhysik Rosenweg2
Universita¨tBielefeld 22869Schenefeld,Germany
Universita¨tsstrasse25
33615Bielefeld,Germany ClausKiefer
Fakulta¨tfu¨rPhysik
DomenicoGiulini Universita¨tFreiburg
Institutfu¨rTheoretischePhysik Hermann-Herder-Strasse3
Universita¨tZu¨rich 79104Freiburg,Germany
WinterthurerStrasse190
8057Zu¨rich,Switzerland Ion-OlimpiuStamatescu
FESt,Schmeilweg5
69118Heidelberg,Germany
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Decoherence:theoretical,experimental,andconceptualproblems;
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Preface
TheworkshopDecoherence: Theoretical, Experimental, and ConceptualProb
lems tookplace atthe Zentrumfur interdisziplinareForschung(Centreforin
terdisciplinaryresearch,ZiF) at BielefeldUniversity(November 10-14,1998).
The concept of decoherence has attracted much attention during recent
years andthis workshop wasintendedto bringtogetheradiverse collection of
researchers to exchange new ideas concerning various approaches to current
problems.
Decoherenceisa quantum-mechanicalprocess that dynamically describes
the apparent loss of quantum coherence due to coupling of the system un
der observationto other degrees offreedom, which escapedirect observation.
Typicalexamplesare givenbyscatteringprocesses, in whichtheoff-scattered
particles (and/or radiation) are not detected. In such processes quantum
correlations between the observed system and its environment become delo
calized in an effectively irreversible manner. Such quantum correlations can
neither be seen by observations on one or the other system alone, nor inter
preted as statistical correlations between existing (i.e., defined, but possibly
unknown) states of local systems. They truly reflect the non-local nature of
quantum mechanics.
The process of decoherence is of major importance for both theoretical
and experimental.physics, and has direct implications in closesciences such
as chemistry and biology. It is also linked to some fundamental problems,
such as that of quantum measurement, observation and related philosoph
ical issues. These topics have been the subject of a long-term study by a
group at the interdisciplinary researchinstitute FESt ("Forschungsstatte der
Evangelischen Studiengemeinschaft", Heidelberg), whose aim is to promote
interdisciplinary projects and interactions between various fields in natural
sciences and the humanities.
The organizationofthe workshop at ZiF is a consequence ofthe activity
of the above-mentioned study group at FESt and attests for the interest
and engagement in interdisciplinary projects at both institutions. Our aim
was to provide a platform for a thorough exchange of ideas on all aspects
of decoherence. Hence people from different fields.were invited and much
emphasis was laid on discussions.
VI Preface
Contents
I. General Introduction
Elements of Environmental Decoherence
E. Joos 1
The Meaning of Decoherence
H.D. Zeh 19
II. Theoretical Aspects
Continuous Fuzzy Measurement of Energy:
Realization and Application
J. Audretsch 43
Slow Decoherence of Superpositions of Macroscopically
Distinct States
D. Braun, P.A. Braun, and F. Haake 55
Grey Solitons in Bose-Einstein Condensates as Mesoscopic Particles
T. Busch and J.R. Anglin 67
Decoherence Through Coupling to the Radiation Field
D. Diirr and H. Spohn 77
States, Symmetries and Superselection
D. Giulini 87
Decoherence in Situations Involving the Gravitational Field
C. Kiefer 101
Moving Quantum Agents in a Finite Environment
1. Kim and G. Mahler 113
Mathematical Aspects of Decoherence
J. Kupsch 125
VIII Table of Contents
Table of Contents IX
List of Contributors
James R. Anglin Fritz Haake
Universitat Innsbruck Universitat Gesamthochschule Essen
Institut fur Experimentalphysik FB 7 - Physik
Technikerstr. 25 D - 45117 Essen, Germany
A - 6020 Innsbruck, Austria
Franz Hasselbach
Jiirgen Audretsch Universitat Tiibingen
Universitat Konstanz Institut fur Angewandte Physik
Fakultat fur Physik Aufder Morgenstelle 12
Postfach 5560 D - 72076 Tiibingen, Germany
D - 78434 Konstanz, Germany
Erich Joos
Marcello Cini
Rosenweg 2
Universita La Sapienza
D - 22869 Schenefeld, Germany
Dipartimento di Fisica
Piazza A. Moro
Claus Kiefer
I - 00185 Rome, Italy
Universitat Freiburg
Fakultat fur Physik
Lajos Di6si
Hermann-Herder-Str. 3
KFKI Research Institute
D - 79104 Freiburg, Germany
for Particle and Nuclear Physics
P.O. Box 49
H - 1525 Budapest 114, Hungary Joachim Kupsch
Universitat Kaiserslautern
Nicolas Gisin Fachbereich Physik
University of Geneva Erwin-Schrodinger-Str.
Group of Applied Physics D - 67663 Kaiserslautern, Germany
CH - 1211 Geneva 4, Switzerland
Giinter Mahler
Domenico Giulini Universitat Stuttgart
Universitat Zurich Institut fur Theoretische Physik und
Institut fur Theoretische Physik Synergetik
Winterthurerstr. 190 Pfaffenwaldring 57jlV
CH - 80.57 Zurich, Switzerland D - 70550 Stuttgart, Germany