Effective descriptions of complex quantum systems: Path integrals and operator ordering problems

Research output: Contribution to journalArticleResearchpeer review

Authors

External Research Organisations

  • University of Augsburg
View graph of relations

Details

Original languageEnglish
Pages (from-to)578-590
Number of pages13
JournalAnnalen der Physik (Leipzig)
Volume14
Issue number9-10
Publication statusPublished - 1 Sept 2005
Externally publishedYes

Abstract

We study certain aspects of the effective, occasionally called collective, description of complex quantum systems within the framework of the path integral formalism, in which the environment is integrated out. Generalising the standard Feynman-Vernon Caldeira-Leggett model to include a non-linear coupling between "particle" and environment, and considering a particular spectral density of the coupling, a coordinate-dependent mass (or velocity-dependent potential) is obtained. The related effective quantum theory, which depends on the proper discretisation of the path integral, is derived and discussed. As a result, we find that in general a simple effective low-energy Hamiltonian, in which only the coordinate-dependent mass enters, cannot be formulated. The quantum theory of weakly coupled superconductors and the quantum dynamics of vortices in Josephson junction arrays are physical examples where these considerations, in principle, are of relevance.

Keywords

    Coordinate-dependent mass, Effective quantum theories, Operator ordering

ASJC Scopus subject areas

Cite this

Effective descriptions of complex quantum systems: Path integrals and operator ordering problems. / Eckern, Ulrich; Gruber, Michael J.; Schwab, Peter.
In: Annalen der Physik (Leipzig), Vol. 14, No. 9-10, 01.09.2005, p. 578-590.

Research output: Contribution to journalArticleResearchpeer review

Download
@article{8c20119a9c684d5e96a3debe1b8377ac,
title = "Effective descriptions of complex quantum systems: Path integrals and operator ordering problems",
abstract = "We study certain aspects of the effective, occasionally called collective, description of complex quantum systems within the framework of the path integral formalism, in which the environment is integrated out. Generalising the standard Feynman-Vernon Caldeira-Leggett model to include a non-linear coupling between {"}particle{"} and environment, and considering a particular spectral density of the coupling, a coordinate-dependent mass (or velocity-dependent potential) is obtained. The related effective quantum theory, which depends on the proper discretisation of the path integral, is derived and discussed. As a result, we find that in general a simple effective low-energy Hamiltonian, in which only the coordinate-dependent mass enters, cannot be formulated. The quantum theory of weakly coupled superconductors and the quantum dynamics of vortices in Josephson junction arrays are physical examples where these considerations, in principle, are of relevance.",
keywords = "Coordinate-dependent mass, Effective quantum theories, Operator ordering",
author = "Ulrich Eckern and Gruber, {Michael J.} and Peter Schwab",
year = "2005",
month = sep,
day = "1",
doi = "10.1002/andp.200510150",
language = "English",
volume = "14",
pages = "578--590",
journal = "Annalen der Physik (Leipzig)",
issn = "0003-3804",
publisher = "Wiley-Blackwell",
number = "9-10",

}

Download

TY - JOUR

T1 - Effective descriptions of complex quantum systems

T2 - Path integrals and operator ordering problems

AU - Eckern, Ulrich

AU - Gruber, Michael J.

AU - Schwab, Peter

PY - 2005/9/1

Y1 - 2005/9/1

N2 - We study certain aspects of the effective, occasionally called collective, description of complex quantum systems within the framework of the path integral formalism, in which the environment is integrated out. Generalising the standard Feynman-Vernon Caldeira-Leggett model to include a non-linear coupling between "particle" and environment, and considering a particular spectral density of the coupling, a coordinate-dependent mass (or velocity-dependent potential) is obtained. The related effective quantum theory, which depends on the proper discretisation of the path integral, is derived and discussed. As a result, we find that in general a simple effective low-energy Hamiltonian, in which only the coordinate-dependent mass enters, cannot be formulated. The quantum theory of weakly coupled superconductors and the quantum dynamics of vortices in Josephson junction arrays are physical examples where these considerations, in principle, are of relevance.

AB - We study certain aspects of the effective, occasionally called collective, description of complex quantum systems within the framework of the path integral formalism, in which the environment is integrated out. Generalising the standard Feynman-Vernon Caldeira-Leggett model to include a non-linear coupling between "particle" and environment, and considering a particular spectral density of the coupling, a coordinate-dependent mass (or velocity-dependent potential) is obtained. The related effective quantum theory, which depends on the proper discretisation of the path integral, is derived and discussed. As a result, we find that in general a simple effective low-energy Hamiltonian, in which only the coordinate-dependent mass enters, cannot be formulated. The quantum theory of weakly coupled superconductors and the quantum dynamics of vortices in Josephson junction arrays are physical examples where these considerations, in principle, are of relevance.

KW - Coordinate-dependent mass

KW - Effective quantum theories

KW - Operator ordering

UR - http://www.scopus.com/inward/record.url?scp=25844518382&partnerID=8YFLogxK

U2 - 10.1002/andp.200510150

DO - 10.1002/andp.200510150

M3 - Article

AN - SCOPUS:25844518382

VL - 14

SP - 578

EP - 590

JO - Annalen der Physik (Leipzig)

JF - Annalen der Physik (Leipzig)

SN - 0003-3804

IS - 9-10

ER -

By the same author(s)