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

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OriginalspracheEnglisch
Seiten (von - bis)578-590
Seitenumfang13
FachzeitschriftAnnalen der Physik (Leipzig)
Jahrgang14
Ausgabenummer9-10
PublikationsstatusVeröffentlicht - 1 Sept. 2005
Extern publiziertJa

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.

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Effective descriptions of complex quantum systems: Path integrals and operator ordering problems. / Eckern, Ulrich; Gruber, Michael J.; Schwab, Peter.
in: Annalen der Physik (Leipzig), Jahrgang 14, Nr. 9-10, 01.09.2005, S. 578-590.

Publikation: Beitrag in FachzeitschriftArtikelForschungPeer-Review

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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

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