http://www.cnr.it/ontology/cnr/individuo/prodotto/ID254996

Parametric representation of open quantum systems and cross-over from quantum to classical environment (Articolo in rivista)

Type

Prodotto della ricerca (Classe)
Articolo in rivista (Classe)

Label

Parametric representation of open quantum systems and cross-over from quantum to classical environment (Articolo in rivista) (literal)

Anno

2013-01-01T00:00:00+01:00 (literal)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#doi

10.1073/pnas.1217776110 (literal)

Alternative label

Dario Calvani (a,b); Alessandro Cuccoli (a,b); Nikitas I. Gidopoulos (c,d); Paola Verrucchi (a,b,e) (2013)
Parametric representation of open quantum systems and cross-over from quantum to classical environment
in Proceedings of the National Academy of Sciences of the United States of America
(literal)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#autori

Dario Calvani (a,b); Alessandro Cuccoli (a,b); Nikitas I. Gidopoulos (c,d); Paola Verrucchi (a,b,e) (literal)

Pagina inizio

6748 (literal)

Pagina fine

6753 (literal)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#altreInformazioni

ISI Document Delivery No.: 140TE Times Cited: 0 Cited Reference Count: 69 Calvani, Dario Cuccoli, Alessandro Gidopoulos, Nikitas I. Verrucchi, Paola Italian Ministry of Education, University, and Research [2008PARRTS 003]; Consiglio Nazionale delle Ricerche The authors thank T. J. G. Apollaro, L. Banchi, F. Bonechi, M. Long, A. Messina, M. Palma, M. Tarlini, and R. Vaia for fruitful discussions and valuable suggestions. Financial support for this work was provided by the Italian Ministry of Education, University, and Research in the framework of the Progetti di Ricerca di Interesse Nazionale 2008, Program Contract 2008PARRTS 003. P. V. acknowledges financial support from the Consiglio Nazionale delle Ricerche, in the framework of the Short Term Mobility Program 2010. Natl acad sciences Washington (literal)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#url

http://www.pnas.org/content/110/17/6748 (literal)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#numeroVolume

110 (literal)

Rivista

Proceedings of the National Academy of Sciences of the United States of America (Rivista)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#pagineTotali

6 (literal)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#numeroFascicolo

17 (literal)

Note

ISI Web of Science (WOS) (literal)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#affiliazioni

(a) Dipartimento di Fisica e Astronomia, Università di Firenze, I-50019 Sesto Fiorentino, Italy; (b) Sezione di Firenze dell'Istituto Nazionale di Fisica Nucleare, I-50019 Sesto Fiorentino, Italy; (c) ISIS, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Didcot OX11 0QX, United Kingdom; (d) Department of Physics, Durham University, Durham DH1 3LE, United Kingdom; (e) Istituto dei Sistemi Complessi, Consiglio Nazionale delle Ricerche, I-50019 Sesto Fiorentino, Italy (literal)

Titolo

Parametric representation of open quantum systems and cross-over from quantum to classical environment (literal)

Abstract

The behavior of most physical systems is affected by their natural surroundings. A quantum system with an environment is referred to as open, and its study varies according to the classical or quantum description adopted for the environment. We propose an approach to open quantum systems that allows us to follow the cross-over from quantum to classical environments; to achieve this, we devise an exact parametric representation of the principal system, based on generalized coherent states for the environment. The method is applied to the s = 1/2 Heisenberg star with frustration, where the quantum character of the environment varies with the couplings entering the Hamiltonian H. We find that when the star is in an eigenstate of H, the central spin behaves as if it were in an effective magnetic field, pointing in the direction set by the environmental coherent-state angle variables (theta, phi), and broadened according to their quantum probability distribution. Such distribution is independent of phi, whereas as a function of theta is seen to get narrower as the quantum character of the environment is reduced, collapsing into a Dirac-delta function in the classical limit. In such limit, because phi is left undetermined, the Von Neumann entropy of the central spin remains finite; in fact, it is equal to the entanglement of the original fully quantum model, a result that establishes a relation between this latter quantity and the Berry phase characterizing the dynamics of the central spin in the effective magnetic field. (literal)

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