Reduction of the wave packet: Preferred observable and decoherence time scale
Abstract
Environmentinduced destruction of quantum coherence is investigated in a simple model where the system is a harmonic oscillator, the environment is a collection of harmonic oscillators, and the interaction between them is linear in the position coordinate of the system. We study decoherence for initial states consisting of coherent superpositions of two Gaussian wave packets in either position or momentum. A new measure of the effectiveness of decoherence appropriate to the model and choice of initial conditions is proposed. By studying the dependence of the decoherence rate on the location of the initial peaks of the Wigner function, we clarify the sense in which position is a preferred observable even though position eigenstates are not the pointer states of this model. We analyze decoherence in the lowtemperature regime and show that the usual hightemperature'' approximation is remarkably accurate in its domain of applicability. We also examine the relationship between the decoherence process and the frequency distribution of the environment oscillators (in particular, we focus attention on a specific supraOhmic'' environment). Implications of our results for the quantum to classical transition in various contexts are briefly explored.
 Authors:

 Theoretical Astrophysics, T6, Mail Stop B288, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
 Publication Date:
 OSTI Identifier:
 7119917
 Resource Type:
 Journal Article
 Journal Name:
 Physical Review, D (Particles Fields); (United States)
 Additional Journal Information:
 Journal Volume: 47:2; Journal ID: ISSN 05562821
 Country of Publication:
 United States
 Language:
 English
 Subject:
 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; QUANTUM MECHANICS; HARMONIC OSCILLATOR MODELS; EIGENSTATES; HAMILTONIANS; HILBERT SPACE; SUPERSELECTION RULES; TEMPERATURE DEPENDENCE; WAVE PACKETS; BANACH SPACE; MATHEMATICAL MODELS; MATHEMATICAL OPERATORS; MATHEMATICAL SPACE; MECHANICS; QUANTUM OPERATORS; SELECTION RULES; SPACE; 661100*  Classical & Quantum Mechanics (1992)
Citation Formats
Paz, J P, Habib, S, and Zurek, W H. Reduction of the wave packet: Preferred observable and decoherence time scale. United States: N. p., 1993.
Web. doi:10.1103/PhysRevD.47.488.
Paz, J P, Habib, S, & Zurek, W H. Reduction of the wave packet: Preferred observable and decoherence time scale. United States. doi:10.1103/PhysRevD.47.488.
Paz, J P, Habib, S, and Zurek, W H. Fri .
"Reduction of the wave packet: Preferred observable and decoherence time scale". United States. doi:10.1103/PhysRevD.47.488.
@article{osti_7119917,
title = {Reduction of the wave packet: Preferred observable and decoherence time scale},
author = {Paz, J P and Habib, S and Zurek, W H},
abstractNote = {Environmentinduced destruction of quantum coherence is investigated in a simple model where the system is a harmonic oscillator, the environment is a collection of harmonic oscillators, and the interaction between them is linear in the position coordinate of the system. We study decoherence for initial states consisting of coherent superpositions of two Gaussian wave packets in either position or momentum. A new measure of the effectiveness of decoherence appropriate to the model and choice of initial conditions is proposed. By studying the dependence of the decoherence rate on the location of the initial peaks of the Wigner function, we clarify the sense in which position is a preferred observable even though position eigenstates are not the pointer states of this model. We analyze decoherence in the lowtemperature regime and show that the usual hightemperature'' approximation is remarkably accurate in its domain of applicability. We also examine the relationship between the decoherence process and the frequency distribution of the environment oscillators (in particular, we focus attention on a specific supraOhmic'' environment). Implications of our results for the quantum to classical transition in various contexts are briefly explored.},
doi = {10.1103/PhysRevD.47.488},
journal = {Physical Review, D (Particles Fields); (United States)},
issn = {05562821},
number = ,
volume = 47:2,
place = {United States},
year = {1993},
month = {1}
}